<row>
<entry role="catalog_table_entry"><para role="column_definition">
- <structfield>heap_tuples_written</structfield> <type>bigint</type>
+ <structfield>heap_tuples_inserted</structfield> <type>bigint</type>
</para>
<para>
- Number of heap tuples written.
+ Number of heap tuples inserted.
This counter only advances when the phase is
<literal>seq scanning heap</literal>,
- <literal>index scanning heap</literal>
- or <literal>writing new heap</literal>.
+ <literal>index scanning heap</literal>,
+ <literal>writing new heap</literal>
+ or <literal>catch-up</literal>.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>heap_tuples_updated</structfield> <type>bigint</type>
+ </para>
+ <para>
+ Number of heap tuples updated.
+ This counter only advances when the phase is <literal>catch-up</literal>.
+ </para></entry>
+ </row>
+
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>heap_tuples_deleted</structfield> <type>bigint</type>
+ </para>
+ <para>
+ Number of heap tuples deleted.
+ This counter only advances when the phase is <literal>catch-up</literal>.
</para></entry>
</row>
<command>REPACK</command> is currently writing the new heap.
</entry>
</row>
+ <row>
+ <entry><literal>catch-up</literal></entry>
+ <entry>
+ <command>REPACK CONCURRENTLY</command> is currently processing the DML
+ commands that other transactions executed during any of the preceding
+ phases.
+ </entry>
+ </row>
<row>
<entry><literal>swapping relation files</literal></entry>
<entry>
<title>Caveats</title>
<para>
- Some DDL commands, currently only <link linkend="sql-truncate"><command>TRUNCATE</command></link> and the
- table-rewriting forms of <link linkend="sql-altertable"><command>ALTER TABLE</command></link>, are not
+ Some commands, currently only <link linkend="sql-truncate"><command>TRUNCATE</command></link>, the
+ table-rewriting forms of <link linkend="sql-altertable"><command>ALTER
+ TABLE</command></link> and <command>REPACK</command> with
+ the <literal>CONCURRENTLY</literal> option, are not
MVCC-safe. This means that after the truncation or rewrite commits, the
table will appear empty to concurrent transactions, if they are using a
- snapshot taken before the DDL command committed. This will only be an
+ snapshot taken before the command committed. This will only be an
issue for a transaction that did not access the table in question
- before the DDL command started — any transaction that has done so
+ before the command started — any transaction that has done so
would hold at least an <literal>ACCESS SHARE</literal> table lock,
- which would block the DDL command until that transaction completes.
+ which would block the truncating or rewriting command until that transaction completes.
So these commands will not cause any apparent inconsistency in the
table contents for successive queries on the target table, but they
could cause visible inconsistency between the contents of the target
VERBOSE [ <replaceable class="parameter">boolean</replaceable> ]
ANALYZE [ <replaceable class="parameter">boolean</replaceable> ]
+ CONCURRENTLY [ <replaceable class="parameter">boolean</replaceable> ]
<phrase>and <replaceable class="parameter">table_and_columns</replaceable> is:</phrase>
processes every table and materialized view in the current database that
the current user has the <literal>MAINTAIN</literal> privilege on. This
form of <command>REPACK</command> cannot be executed inside a transaction
- block.
+ block. Also, this form is not allowed if
+ the <literal>CONCURRENTLY</literal> option is used.
</para>
<para>
When a table is being repacked, an <literal>ACCESS EXCLUSIVE</literal> lock
is acquired on it. This prevents any other database operations (both reads
and writes) from operating on the table until the <command>REPACK</command>
- is finished.
+ is finished. If you want to keep the table accessible during the repacking,
+ consider using the <literal>CONCURRENTLY</literal> option.
</para>
<refsect2 id="sql-repack-notes-on-clustering" xreflabel="Notes on Clustering">
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>CONCURRENTLY</literal></term>
+ <listitem>
+ <para>
+ Allow other transactions to use the table while it is being repacked.
+ </para>
+
+ <para>
+ Internally, <command>REPACK</command> copies the contents of the table
+ (ignoring dead tuples) into a new file, sorted by the specified index,
+ and also creates a new file for each index. Then it swaps the old and
+ new files for the table and all the indexes, and deletes the old
+ files. The <literal>ACCESS EXCLUSIVE</literal> lock is needed to make
+ sure that the old files do not change during the processing because the
+ changes would get lost due to the swap.
+ </para>
+
+ <para>
+ With the <literal>CONCURRENTLY</literal> option, the <literal>ACCESS
+ EXCLUSIVE</literal> lock is only acquired to swap the table and index
+ files. The data changes that took place during the creation of the new
+ table and index files are captured using logical decoding
+ (<xref linkend="logicaldecoding"/>) and applied before
+ the <literal>ACCESS EXCLUSIVE</literal> lock is requested. Thus the lock
+ is typically held only for the time needed to swap the files, which
+ should be pretty short. However, the time might still be noticeable if
+ too many data changes have been done to the table while
+ <command>REPACK</command> was waiting for the lock: those changes must
+ be processed just before the files are swapped, while the
+ <literal>ACCESS EXCLUSIVE</literal> lock is being held.
+ </para>
+
+ <para>
+ Note that <command>REPACK</command> with the
+ <literal>CONCURRENTLY</literal> option does not try to order the rows
+ inserted into the table after the repacking started. Also
+ note <command>REPACK</command> might fail to complete due to DDL
+ commands executed on the table by other transactions during the
+ repacking.
+ </para>
+
+ <note>
+ <para>
+ In addition to the temporary space requirements explained in
+ <xref linkend="sql-repack-notes-on-resources"/>,
+ the <literal>CONCURRENTLY</literal> option can add to the usage of
+ temporary space a bit more. The reason is that other transactions can
+ perform DML operations which cannot be applied to the new file until
+ <command>REPACK</command> has copied all the existing tuples from the
+ old file. Thus the tuples inserted into the old file during the copying
+ are also stored separately in a temporary file, until they can be
+ processed.
+ </para>
+ </note>
+
+ <para>
+ The <literal>CONCURRENTLY</literal> option cannot be used in the
+ following cases:
+
+ <itemizedlist>
+ <listitem>
+ <para>
+ The table is <literal>UNLOGGED</literal>.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The table is partitioned.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The table lacks a primary key and index-based replica identity.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The table is a system catalog or a <acronym>TOAST</acronym> table.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ <command>REPACK</command> is executed inside a transaction block.
+ </para>
+ </listitem>
+
+ <listitem>
+ <para>
+ The <link linkend="guc-max-replication-slots"><varname>max_replication_slots</varname></link>
+ configuration parameter does not allow for creation of an additional
+ replication slot.
+ </para>
+ </listitem>
+ </itemizedlist>
+ </para>
+
+ <warning>
+ <para>
+ <command>REPACK</command> with the <literal>CONCURRENTLY</literal>
+ option is not MVCC-safe, see <xref linkend="mvcc-caveats"/> for
+ details.
+ </para>
+ </warning>
+
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><literal>VERBOSE</literal></term>
<listitem>
interfaces \
backend/replication/libpqwalreceiver \
backend/replication/pgoutput \
+ backend/replication/pgrepack \
fe_utils \
bin \
pl \
static XLogRecPtr log_heap_update(Relation reln, Buffer oldbuf,
Buffer newbuf, HeapTuple oldtup,
HeapTuple newtup, HeapTuple old_key_tuple,
- bool all_visible_cleared, bool new_all_visible_cleared);
+ bool all_visible_cleared, bool new_all_visible_cleared,
+ bool walLogical);
#ifdef USE_ASSERT_CHECKING
static void check_lock_if_inplace_updateable_rel(Relation relation,
const ItemPointerData *otid,
uint16 new_infomask,
new_infomask2;
bool changingPart = (options & TABLE_DELETE_CHANGING_PARTITION) != 0;
+ bool walLogical = (options & TABLE_DELETE_NO_LOGICAL) == 0;
bool have_tuple_lock = false;
bool iscombo;
bool all_visible_cleared = false;
* Compute replica identity tuple before entering the critical section so
* we don't PANIC upon a memory allocation failure.
*/
- old_key_tuple = ExtractReplicaIdentity(relation, &tp, true, &old_key_copied);
+ old_key_tuple = walLogical ?
+ ExtractReplicaIdentity(relation, &tp, true, &old_key_copied) : NULL;
/*
* If this is the first possibly-multixact-able operation in the current
xlrec.flags |= XLH_DELETE_CONTAINS_OLD_KEY;
}
+ /*
+ * Mark the change as not-for-logical-decoding if caller requested so.
+ *
+ * (This is used for changes that affect relations not visible to
+ * other transactions, such as the transient table during concurrent
+ * repack.)
+ */
+ if (!walLogical)
+ xlrec.flags |= XLH_DELETE_NO_LOGICAL;
+
XLogBeginInsert();
XLogRegisterData(&xlrec, SizeOfHeapDelete);
HeapTuple heaptup;
HeapTuple old_key_tuple = NULL;
bool old_key_copied = false;
+ bool walLogical = (options & TABLE_UPDATE_NO_LOGICAL) == 0;
Page page,
newpage;
BlockNumber block;
newbuf, &oldtup, heaptup,
old_key_tuple,
all_visible_cleared,
- all_visible_cleared_new);
+ all_visible_cleared_new,
+ walLogical);
if (newbuf != buffer)
{
PageSetLSN(newpage, recptr);
log_heap_update(Relation reln, Buffer oldbuf,
Buffer newbuf, HeapTuple oldtup, HeapTuple newtup,
HeapTuple old_key_tuple,
- bool all_visible_cleared, bool new_all_visible_cleared)
+ bool all_visible_cleared, bool new_all_visible_cleared,
+ bool walLogical)
{
xl_heap_update xlrec;
xl_heap_header xlhdr;
suffixlen = 0;
XLogRecPtr recptr;
Page page = BufferGetPage(newbuf);
- bool need_tuple_data = RelationIsLogicallyLogged(reln);
+ bool need_tuple_data = walLogical && RelationIsLogicallyLogged(reln);
bool init;
int bufflags;
static void reform_and_rewrite_tuple(HeapTuple tuple,
Relation OldHeap, Relation NewHeap,
Datum *values, bool *isnull, RewriteState rwstate);
+static void heap_insert_for_repack(HeapTuple tuple, Relation OldHeap,
+ Relation NewHeap, Datum *values, bool *isnull,
+ BulkInsertState bistate);
+static HeapTuple reform_tuple(HeapTuple tuple, Relation OldHeap,
+ Relation NewHeap, Datum *values, bool *isnull);
static bool SampleHeapTupleVisible(TableScanDesc scan, Buffer buffer,
HeapTuple tuple,
heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
Relation OldIndex, bool use_sort,
TransactionId OldestXmin,
+ Snapshot snapshot,
TransactionId *xid_cutoff,
MultiXactId *multi_cutoff,
double *num_tuples,
double *tups_recently_dead)
{
RewriteState rwstate;
+ BulkInsertState bistate;
IndexScanDesc indexScan;
TableScanDesc tableScan;
HeapScanDesc heapScan;
bool *isnull;
BufferHeapTupleTableSlot *hslot;
BlockNumber prev_cblock = InvalidBlockNumber;
+ bool concurrent = snapshot != NULL;
/* Remember if it's a system catalog */
is_system_catalog = IsSystemRelation(OldHeap);
values = palloc_array(Datum, natts);
isnull = palloc_array(bool, natts);
- /* Initialize the rewrite operation */
- rwstate = begin_heap_rewrite(OldHeap, NewHeap, OldestXmin, *xid_cutoff,
- *multi_cutoff);
+ /*
+ * In non-concurrent mode, initialize the rewrite operation. This is not
+ * needed in concurrent mode.
+ */
+ if (!concurrent)
+ rwstate = begin_heap_rewrite(OldHeap, NewHeap, OldestXmin,
+ *xid_cutoff, *multi_cutoff);
+ else
+ rwstate = NULL;
+ /* In concurrent mode, prepare for bulk-insert operation. */
+ if (concurrent)
+ bistate = GetBulkInsertState();
+ else
+ bistate = NULL;
/* Set up sorting if wanted */
if (use_sort)
* Prepare to scan the OldHeap. To ensure we see recently-dead tuples
* that still need to be copied, we scan with SnapshotAny and use
* HeapTupleSatisfiesVacuum for the visibility test.
+ *
+ * In the CONCURRENTLY case, we do regular MVCC visibility tests, using
+ * the snapshot passed by the caller.
*/
if (OldIndex != NULL && !use_sort)
{
tableScan = NULL;
heapScan = NULL;
- indexScan = index_beginscan(OldHeap, OldIndex, SnapshotAny, NULL, 0, 0,
+ indexScan = index_beginscan(OldHeap, OldIndex,
+ snapshot ? snapshot : SnapshotAny,
+ NULL, 0, 0,
SO_NONE);
index_rescan(indexScan, NULL, 0, NULL, 0);
}
pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
PROGRESS_REPACK_PHASE_SEQ_SCAN_HEAP);
- tableScan = table_beginscan(OldHeap, SnapshotAny, 0, (ScanKey) NULL,
+ tableScan = table_beginscan(OldHeap,
+ snapshot ? snapshot : SnapshotAny,
+ 0, (ScanKey) NULL,
SO_NONE);
heapScan = (HeapScanDesc) tableScan;
indexScan = NULL;
buf = hslot->buffer;
/*
- * To be able to guarantee that we can set the hint bit, acquire an
- * exclusive lock on the old buffer. We need the hint bits, set in
- * heapam_relation_copy_for_cluster() -> HeapTupleSatisfiesVacuum(),
- * to be set, as otherwise reform_and_rewrite_tuple() ->
- * rewrite_heap_tuple() will get confused. Specifically,
- * rewrite_heap_tuple() checks for HEAP_XMAX_INVALID in the old tuple
- * to determine whether to check the old-to-new mapping hash table.
- *
- * It'd be better if we somehow could avoid setting hint bits on the
- * old page. One reason to use VACUUM FULL are very bloated tables -
- * rewriting most of the old table during VACUUM FULL doesn't exactly
- * help...
+ * In concurrent mode, our table or index scan has used regular MVCC
+ * visibility test against a snapshot passed by caller; therefore we
+ * don't need another visibility test. In non-concurrent mode
+ * however, we must test the visibility of each tuple we read.
*/
- LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
-
- switch (HeapTupleSatisfiesVacuum(tuple, OldestXmin, buf))
+ if (!concurrent)
{
- case HEAPTUPLE_DEAD:
- /* Definitely dead */
- isdead = true;
- break;
- case HEAPTUPLE_RECENTLY_DEAD:
- *tups_recently_dead += 1;
- pg_fallthrough;
- case HEAPTUPLE_LIVE:
- /* Live or recently dead, must copy it */
- isdead = false;
- break;
- case HEAPTUPLE_INSERT_IN_PROGRESS:
+ /*
+ * To be able to guarantee that we can set the hint bit, acquire
+ * an exclusive lock on the old buffer. We need the hint bits, set
+ * in heapam_relation_copy_for_cluster() ->
+ * HeapTupleSatisfiesVacuum(), to be set, as otherwise
+ * reform_and_rewrite_tuple() -> rewrite_heap_tuple() will get
+ * confused. Specifically, rewrite_heap_tuple() checks for
+ * HEAP_XMAX_INVALID in the old tuple to determine whether to
+ * check the old-to-new mapping hash table.
+ *
+ * It'd be better if we somehow could avoid setting hint bits on
+ * the old page. One reason to use VACUUM FULL are very bloated
+ * tables - rewriting most of the old table during VACUUM FULL
+ * doesn't exactly help...
+ */
+ LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
- /*
- * Since we hold exclusive lock on the relation, normally the
- * only way to see this is if it was inserted earlier in our
- * own transaction. However, it can happen in system
- * catalogs, since we tend to release write lock before commit
- * there. Give a warning if neither case applies; but in any
- * case we had better copy it.
- */
- if (!is_system_catalog &&
- !TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple->t_data)))
- elog(WARNING, "concurrent insert in progress within table \"%s\"",
- RelationGetRelationName(OldHeap));
- /* treat as live */
- isdead = false;
- break;
- case HEAPTUPLE_DELETE_IN_PROGRESS:
+ switch (HeapTupleSatisfiesVacuum(tuple, OldestXmin, buf))
+ {
+ case HEAPTUPLE_DEAD:
+ /* Definitely dead */
+ isdead = true;
+ break;
+ case HEAPTUPLE_RECENTLY_DEAD:
+ *tups_recently_dead += 1;
+ pg_fallthrough;
+ case HEAPTUPLE_LIVE:
+ /* Live or recently dead, must copy it */
+ isdead = false;
+ break;
+ case HEAPTUPLE_INSERT_IN_PROGRESS:
- /*
- * Similar situation to INSERT_IN_PROGRESS case.
- */
- if (!is_system_catalog &&
- !TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetUpdateXid(tuple->t_data)))
- elog(WARNING, "concurrent delete in progress within table \"%s\"",
- RelationGetRelationName(OldHeap));
- /* treat as recently dead */
- *tups_recently_dead += 1;
- isdead = false;
- break;
- default:
- elog(ERROR, "unexpected HeapTupleSatisfiesVacuum result");
- isdead = false; /* keep compiler quiet */
- break;
- }
+ /*
+ * As long as we hold exclusive lock on the relation,
+ * normally the only way to see this is if it was inserted
+ * earlier in our own transaction. However, it can happen
+ * in system catalogs, since we tend to release write lock
+ * before commit there. Give a warning if neither case
+ * applies; but in any case we had better copy it.
+ */
+ if (!is_system_catalog &&
+ !TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple->t_data)))
+ elog(WARNING, "concurrent insert in progress within table \"%s\"",
+ RelationGetRelationName(OldHeap));
+ /* treat as live */
+ isdead = false;
+ break;
+ case HEAPTUPLE_DELETE_IN_PROGRESS:
- LockBuffer(buf, BUFFER_LOCK_UNLOCK);
+ /*
+ * Similar situation to INSERT_IN_PROGRESS case.
+ */
+ if (!is_system_catalog &&
+ !TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetUpdateXid(tuple->t_data)))
+ elog(WARNING, "concurrent delete in progress within table \"%s\"",
+ RelationGetRelationName(OldHeap));
+ /* treat as recently dead */
+ *tups_recently_dead += 1;
+ isdead = false;
+ break;
+ default:
+ elog(ERROR, "unexpected HeapTupleSatisfiesVacuum result");
+ isdead = false; /* keep compiler quiet */
+ break;
+ }
- if (isdead)
- {
- *tups_vacuumed += 1;
- /* heap rewrite module still needs to see it... */
- if (rewrite_heap_dead_tuple(rwstate, tuple))
+ LockBuffer(buf, BUFFER_LOCK_UNLOCK);
+
+ if (isdead)
{
- /* A previous recently-dead tuple is now known dead */
*tups_vacuumed += 1;
- *tups_recently_dead -= 1;
+ /* heap rewrite module still needs to see it... */
+ if (rewrite_heap_dead_tuple(rwstate, tuple))
+ {
+ /* A previous recently-dead tuple is now known dead */
+ *tups_vacuumed += 1;
+ *tups_recently_dead -= 1;
+ }
+
+ continue;
}
- continue;
}
*num_tuples += 1;
{
const int ct_index[] = {
PROGRESS_REPACK_HEAP_TUPLES_SCANNED,
- PROGRESS_REPACK_HEAP_TUPLES_WRITTEN
+ PROGRESS_REPACK_HEAP_TUPLES_INSERTED
};
int64 ct_val[2];
- reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
- values, isnull, rwstate);
+ if (!concurrent)
+ reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
+ values, isnull, rwstate);
+ else
+ heap_insert_for_repack(tuple, OldHeap, NewHeap,
+ values, isnull, bistate);
/*
* In indexscan mode and also VACUUM FULL, report increase in
break;
n_tuples += 1;
- reform_and_rewrite_tuple(tuple,
- OldHeap, NewHeap,
- values, isnull,
- rwstate);
+ if (!concurrent)
+ reform_and_rewrite_tuple(tuple,
+ OldHeap, NewHeap,
+ values, isnull,
+ rwstate);
+ else
+ heap_insert_for_repack(tuple, OldHeap, NewHeap,
+ values, isnull, bistate);
+
/* Report n_tuples */
- pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_WRITTEN,
+ pgstat_progress_update_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED,
n_tuples);
}
}
/* Write out any remaining tuples, and fsync if needed */
- end_heap_rewrite(rwstate);
+ if (rwstate)
+ end_heap_rewrite(rwstate);
+ if (bistate)
+ FreeBulkInsertState(bistate);
/* Clean up */
pfree(values);
reform_and_rewrite_tuple(HeapTuple tuple,
Relation OldHeap, Relation NewHeap,
Datum *values, bool *isnull, RewriteState rwstate)
+{
+ HeapTuple newtuple;
+
+ newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+
+ /* The heap rewrite module does the rest */
+ rewrite_heap_tuple(rwstate, tuple, newtuple);
+
+ heap_freetuple(newtuple);
+}
+
+/*
+ * Insert tuple when processing REPACK CONCURRENTLY.
+ *
+ * rewriteheap.c is not used in the CONCURRENTLY case because it'd be
+ * difficult to do the same in the catch-up phase (as the logical
+ * decoding does not provide us with sufficient visibility
+ * information). Thus we must use heap_insert() both during the
+ * catch-up and here.
+ *
+ * We pass the NO_LOGICAL flag to heap_insert() in order to skip logical
+ * decoding: as soon as REPACK CONCURRENTLY swaps the relation files, it drops
+ * this relation, so no logical replication subscription should need the data.
+ *
+ * BulkInsertState is used because many tuples are inserted in the typical
+ * case.
+ */
+static void
+heap_insert_for_repack(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
+ Datum *values, bool *isnull, BulkInsertState bistate)
+{
+ HeapTuple newtuple;
+
+ newtuple = reform_tuple(tuple, OldHeap, NewHeap, values, isnull);
+
+ heap_insert(NewHeap, newtuple, GetCurrentCommandId(true),
+ HEAP_INSERT_NO_LOGICAL, bistate);
+
+ heap_freetuple(newtuple);
+}
+
+/*
+ * Subroutine for reform_and_rewrite_tuple and heap_insert_for_repack.
+ *
+ * Deform the given tuple, set values of dropped columns to NULL, form a new
+ * tuple and return it. If no attributes need to be changed in this way, a
+ * copy of the original tuple is returned. Caller is responsible for freeing
+ * the returned tuple.
+ *
+ * XXX this coding assumes that both relations have the same tupledesc.
+ */
+static HeapTuple
+reform_tuple(HeapTuple tuple, Relation OldHeap, Relation NewHeap,
+ Datum *values, bool *isnull)
{
TupleDesc oldTupDesc = RelationGetDescr(OldHeap);
TupleDesc newTupDesc = RelationGetDescr(NewHeap);
- HeapTuple copiedTuple;
- int i;
+ bool needs_reform = false;
+
+ /* Skip work if the tuple doesn't need any attributes changed */
+ for (int i = 0; i < newTupDesc->natts; i++)
+ {
+ if (TupleDescCompactAttr(newTupDesc, i)->attisdropped &&
+ !heap_attisnull(tuple, i + 1, newTupDesc))
+ needs_reform = true;
+ }
+ if (!needs_reform)
+ return heap_copytuple(tuple);
heap_deform_tuple(tuple, oldTupDesc, values, isnull);
- /* Be sure to null out any dropped columns */
- for (i = 0; i < newTupDesc->natts; i++)
+ for (int i = 0; i < newTupDesc->natts; i++)
{
if (TupleDescCompactAttr(newTupDesc, i)->attisdropped)
isnull[i] = true;
}
- copiedTuple = heap_form_tuple(newTupDesc, values, isnull);
-
- /* The heap rewrite module does the rest */
- rewrite_heap_tuple(rwstate, tuple, copiedTuple);
-
- heap_freetuple(copiedTuple);
+ return heap_form_tuple(newTupDesc, values, isnull);
}
/*
uint32 options = HEAP_INSERT_SKIP_FSM;
/*
- * While rewriting the heap for VACUUM FULL / CLUSTER, make sure data
- * for the TOAST table are not logically decoded. The main heap is
- * WAL-logged as XLOG FPI records, which are not logically decoded.
+ * While rewriting the heap for REPACK, make sure data for the TOAST
+ * table are not logically decoded. The main heap is WAL-logged as
+ * XLOG FPI records, which are not logically decoded.
*/
options |= HEAP_INSERT_NO_LOGICAL;
WHEN 2 THEN 'index scanning heap'
WHEN 3 THEN 'sorting tuples'
WHEN 4 THEN 'writing new heap'
- WHEN 5 THEN 'swapping relation files'
- WHEN 6 THEN 'rebuilding index'
- WHEN 7 THEN 'performing final cleanup'
+ WHEN 5 THEN 'catch-up'
+ WHEN 6 THEN 'swapping relation files'
+ WHEN 7 THEN 'rebuilding index'
+ WHEN 8 THEN 'performing final cleanup'
END AS phase,
CAST(S.param3 AS oid) AS repack_index_relid,
S.param4 AS heap_tuples_scanned,
- S.param5 AS heap_tuples_written,
- S.param6 AS heap_blks_total,
- S.param7 AS heap_blks_scanned,
- S.param8 AS index_rebuild_count
+ S.param5 AS heap_tuples_inserted,
+ S.param6 AS heap_tuples_updated,
+ S.param7 AS heap_tuples_deleted,
+ S.param8 AS heap_blks_total,
+ S.param9 AS heap_blks_scanned,
+ S.param10 AS index_rebuild_count
FROM pg_stat_get_progress_info('REPACK') AS S
LEFT JOIN pg_database D ON S.datid = D.oid;
phase,
repack_index_relid AS cluster_index_relid,
heap_tuples_scanned,
- heap_tuples_written,
+ heap_tuples_inserted + heap_tuples_updated AS heap_tuples_written,
heap_blks_total,
heap_blks_scanned,
index_rebuild_count
propgraphcmds.o \
publicationcmds.o \
repack.o \
+ repack_worker.o \
schemacmds.o \
seclabel.o \
sequence.o \
refresh_by_heap_swap(Oid matviewOid, Oid OIDNewHeap, char relpersistence)
{
finish_heap_swap(matviewOid, OIDNewHeap, false, false, true, true,
+ true, /* reindex */
RecentXmin, ReadNextMultiXactId(), relpersistence);
}
'propgraphcmds.c',
'publicationcmds.c',
'repack.c',
+ 'repack_worker.c',
'schemacmds.c',
'seclabel.c',
'sequence.c',
* REPACK a table; formerly known as CLUSTER. VACUUM FULL also uses
* parts of this code.
*
+ * There are two somewhat different ways to rewrite a table. In non-
+ * concurrent mode, it's easy: take AccessExclusiveLock, create a new
+ * transient relation, copy the tuples over to the relfilenode of the new
+ * relation, swap the relfilenodes, then drop the old relation.
+ *
+ * In concurrent mode, we lock the table with only ShareUpdateExclusiveLock,
+ * then do an initial copy as above. However, while the tuples are being
+ * copied, concurrent transactions could modify the table. To cope with those
+ * changes, we rely on logical decoding to obtain them from WAL. A bgworker
+ * consumes WAL while the initial copy is ongoing (to prevent excessive WAL
+ * from being reserved), and accumulates the changes in a file. Once the
+ * initial copy is complete, we read the changes from the file and re-apply
+ * them on the new heap. Then we upgrade our ShareUpdateExclusiveLock to
+ * AccessExclusiveLock and swap the relfilenodes. This way, the time we hold
+ * a strong lock on the table is much reduced, and the bloat is eliminated.
+ *
*
* Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
* Portions Copyright (c) 1994-5, Regents of the University of California
#include "catalog/namespace.h"
#include "catalog/objectaccess.h"
#include "catalog/pg_am.h"
+#include "catalog/pg_constraint.h"
#include "catalog/pg_inherits.h"
#include "catalog/toasting.h"
#include "commands/defrem.h"
#include "commands/progress.h"
#include "commands/repack.h"
+#include "commands/repack_internal.h"
#include "commands/tablecmds.h"
#include "commands/vacuum.h"
+#include "executor/executor.h"
+#include "libpq/pqformat.h"
+#include "libpq/pqmq.h"
#include "miscadmin.h"
#include "optimizer/optimizer.h"
#include "pgstat.h"
#include "storage/bufmgr.h"
#include "storage/lmgr.h"
#include "storage/predicate.h"
+#include "storage/proc.h"
#include "utils/acl.h"
#include "utils/fmgroids.h"
#include "utils/guc.h"
+#include "utils/injection_point.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/relmapper.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"
+#include "utils/wait_event_types.h"
/*
* This struct is used to pass around the information on tables to be
Oid indexOid;
} RelToCluster;
+/*
+ * The first file exported by the decoding worker must contain a snapshot, the
+ * following ones contain the data changes.
+ */
+#define WORKER_FILE_SNAPSHOT 0
+
+/*
+ * Information needed to apply concurrent data changes.
+ */
+typedef struct ChangeContext
+{
+ /* The relation the changes are applied to. */
+ Relation cc_rel;
+
+ /* Needed to update indexes of rel_dst. */
+ ResultRelInfo *cc_rri;
+ EState *cc_estate;
+
+ /*
+ * Existing tuples to UPDATE and DELETE are located via this index. We
+ * keep the scankey in partially initialized state to avoid repeated work.
+ * sk_argument is completed on the fly.
+ */
+ Relation cc_ident_index;
+ ScanKey cc_ident_key;
+ int cc_ident_key_nentries;
+
+ /* Sequential number of the file containing the changes. */
+ int cc_file_seq;
+} ChangeContext;
+
+/*
+ * Backend-local information to control the decoding worker.
+ */
+typedef struct DecodingWorker
+{
+ /* The worker. */
+ BackgroundWorkerHandle *handle;
+
+ /* DecodingWorkerShared is in this segment. */
+ dsm_segment *seg;
+
+ /* Handle of the error queue. */
+ shm_mq_handle *error_mqh;
+} DecodingWorker;
+
+/* Pointer to currently running decoding worker. */
+static DecodingWorker *decoding_worker = NULL;
+
+/*
+ * Is there a message sent by a repack worker that the backend needs to
+ * receive?
+ */
+volatile sig_atomic_t RepackMessagePending = false;
+
+static LOCKMODE RepackLockLevel(bool concurrent);
static bool cluster_rel_recheck(RepackCommand cmd, Relation OldHeap,
- Oid indexOid, Oid userid, int options);
-static void rebuild_relation(Relation OldHeap, Relation index, bool verbose);
+ Oid indexOid, Oid userid, LOCKMODE lmode,
+ int options);
+static void check_concurrent_repack_requirements(Relation rel,
+ Oid *ident_idx_p);
+static void rebuild_relation(Relation OldHeap, Relation index, bool verbose,
+ Oid ident_idx);
static void copy_table_data(Relation NewHeap, Relation OldHeap, Relation OldIndex,
- bool verbose, bool *pSwapToastByContent,
- TransactionId *pFreezeXid, MultiXactId *pCutoffMulti);
+ Snapshot snapshot,
+ bool verbose,
+ bool *pSwapToastByContent,
+ TransactionId *pFreezeXid,
+ MultiXactId *pCutoffMulti);
static List *get_tables_to_repack(RepackCommand cmd, bool usingindex,
MemoryContext permcxt);
static List *get_tables_to_repack_partitioned(RepackCommand cmd,
MemoryContext permcxt);
static bool repack_is_permitted_for_relation(RepackCommand cmd,
Oid relid, Oid userid);
+
+static void apply_concurrent_changes(BufFile *file, ChangeContext *chgcxt);
+static void apply_concurrent_insert(Relation rel, TupleTableSlot *slot,
+ ChangeContext *chgcxt);
+static void apply_concurrent_update(Relation rel, TupleTableSlot *spilled_tuple,
+ TupleTableSlot *ondisk_tuple,
+ ChangeContext *chgcxt);
+static void apply_concurrent_delete(Relation rel, TupleTableSlot *slot);
+static void restore_tuple(BufFile *file, Relation relation,
+ TupleTableSlot *slot);
+static void adjust_toast_pointers(Relation relation, TupleTableSlot *dest,
+ TupleTableSlot *src);
+static bool find_target_tuple(Relation rel, ChangeContext *chgcxt,
+ TupleTableSlot *locator,
+ TupleTableSlot *received);
+static void process_concurrent_changes(XLogRecPtr end_of_wal,
+ ChangeContext *chgcxt,
+ bool done);
+static void initialize_change_context(ChangeContext *chgcxt,
+ Relation relation,
+ Oid ident_index_id);
+static void release_change_context(ChangeContext *chgcxt);
+static void rebuild_relation_finish_concurrent(Relation NewHeap, Relation OldHeap,
+ Oid identIdx,
+ TransactionId frozenXid,
+ MultiXactId cutoffMulti);
+static List *build_new_indexes(Relation NewHeap, Relation OldHeap, List *OldIndexes);
+static void copy_index_constraints(Relation old_index, Oid new_index_id,
+ Oid new_heap_id);
static Relation process_single_relation(RepackStmt *stmt,
+ LOCKMODE lockmode,
+ bool isTopLevel,
ClusterParams *params);
static Oid determine_clustered_index(Relation rel, bool usingindex,
const char *indexname);
+
+static void start_repack_decoding_worker(Oid relid);
+static void stop_repack_decoding_worker(void);
+static Snapshot get_initial_snapshot(DecodingWorker *worker);
+
+static void ProcessRepackMessage(StringInfo msg);
static const char *RepackCommandAsString(RepackCommand cmd);
ClusterParams params = {0};
Relation rel = NULL;
MemoryContext repack_context;
+ LOCKMODE lockmode;
List *rtcs;
/* Parse option list */
else if (strcmp(opt->defname, "analyze") == 0 ||
strcmp(opt->defname, "analyse") == 0)
params.options |= defGetBoolean(opt) ? CLUOPT_ANALYZE : 0;
+ else if (strcmp(opt->defname, "concurrently") == 0 &&
+ defGetBoolean(opt))
+ {
+ if (stmt->command != REPACK_COMMAND_REPACK)
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("CONCURRENTLY option not supported for %s",
+ RepackCommandAsString(stmt->command)));
+ params.options |= CLUOPT_CONCURRENT;
+ }
else
ereport(ERROR,
errcode(ERRCODE_SYNTAX_ERROR),
parser_errposition(pstate, opt->location));
}
+ /* Determine the lock mode to use. */
+ lockmode = RepackLockLevel((params.options & CLUOPT_CONCURRENT) != 0);
+
+ if ((params.options & CLUOPT_CONCURRENT) != 0)
+ {
+ /*
+ * Make sure we're not in a transaction block.
+ *
+ * The reason is that repack_setup_logical_decoding() could wait
+ * indefinitely for our XID to complete. (The deadlock detector would
+ * not recognize it because we'd be waiting for ourselves, i.e. no
+ * real lock conflict.) It would be possible to run in a transaction
+ * block if we had no XID, but this restriction is simpler for users
+ * to understand and we don't lose any functionality.
+ */
+ PreventInTransactionBlock(isTopLevel, "REPACK (CONCURRENTLY)");
+ }
+
/*
* If a single relation is specified, process it and we're done ... unless
* the relation is a partitioned table, in which case we fall through.
*/
if (stmt->relation != NULL)
{
- rel = process_single_relation(stmt, ¶ms);
+ rel = process_single_relation(stmt, lockmode, isTopLevel, ¶ms);
if (rel == NULL)
return; /* all done */
}
"REPACK (ANALYZE)"));
/*
- * By here, we know we are in a multi-table situation. In order to avoid
- * holding locks for too long, we want to process each table in its own
- * transaction. This forces us to disallow running inside a user
- * transaction block.
+ * By here, we know we are in a multi-table situation.
+ *
+ * Concurrent processing is currently considered rather special (e.g. in
+ * terms of resources consumed) so it is not performed in bulk.
+ */
+ if (params.options & CLUOPT_CONCURRENT)
+ {
+ if (rel != NULL)
+ {
+ Assert(rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("REPACK (CONCURRENTLY) is not supported for partitioned tables"),
+ errhint("Consider running the command on individual partitions."));
+ }
+ else
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("REPACK (CONCURRENTLY) requires an explicit table name"));
+ }
+
+ /*
+ * In order to avoid holding locks for too long, we want to process each
+ * table in its own transaction. This forces us to disallow running
+ * inside a user transaction block.
*/
PreventInTransactionBlock(isTopLevel, RepackCommandAsString(stmt->command));
"Repack",
ALLOCSET_DEFAULT_SIZES);
+ /*
+ * Since we open a new transaction for each relation, we have to check
+ * that the relation still is what we think it is.
+ *
+ * In single-transaction CLUSTER, we don't need the overhead.
+ */
params.options |= CLUOPT_RECHECK;
/*
* Open the target table, coping with the case where it has been
* dropped.
*/
- rel = try_table_open(rtc->tableOid, AccessExclusiveLock);
+ rel = try_table_open(rtc->tableOid, lockmode);
if (rel == NULL)
{
CommitTransactionCommand();
PushActiveSnapshot(GetTransactionSnapshot());
/* Process this table */
- cluster_rel(stmt->command, rel, rtc->indexOid, ¶ms);
+ cluster_rel(stmt->command, rel, rtc->indexOid, ¶ms, isTopLevel);
/* cluster_rel closes the relation, but keeps lock */
PopActiveSnapshot();
MemoryContextDelete(repack_context);
}
+/*
+ * In the non-concurrent case, we obtain AccessExclusiveLock throughout the
+ * operation to avoid any lock-upgrade hazards. In the concurrent case, we
+ * grab ShareUpdateExclusiveLock (just like VACUUM) for most of the
+ * processing and only acquire AccessExclusiveLock at the end, to swap the
+ * relation -- supposedly for a short time.
+ */
+static LOCKMODE
+RepackLockLevel(bool concurrent)
+{
+ if (concurrent)
+ return ShareUpdateExclusiveLock;
+ else
+ return AccessExclusiveLock;
+}
+
/*
* cluster_rel
*
* If indexOid is InvalidOid, the table will be rewritten in physical order
* instead of index order.
*
+ * Note that, in the concurrent case, the function releases the lock at some
+ * point, in order to get AccessExclusiveLock for the final steps (i.e. to
+ * swap the relation files). To make things simpler, the caller should expect
+ * OldHeap to be closed on return, regardless CLUOPT_CONCURRENT. (The
+ * AccessExclusiveLock is kept till the end of the transaction.)
+ *
* 'cmd' indicates which command is being executed, to be used for error
* messages.
*/
void
cluster_rel(RepackCommand cmd, Relation OldHeap, Oid indexOid,
- ClusterParams *params)
+ ClusterParams *params, bool isTopLevel)
{
Oid tableOid = RelationGetRelid(OldHeap);
+ Relation index;
+ LOCKMODE lmode;
Oid save_userid;
int save_sec_context;
int save_nestlevel;
bool verbose = ((params->options & CLUOPT_VERBOSE) != 0);
bool recheck = ((params->options & CLUOPT_RECHECK) != 0);
- Relation index;
+ bool concurrent = ((params->options & CLUOPT_CONCURRENT) != 0);
+ Oid ident_idx = InvalidOid;
- Assert(CheckRelationLockedByMe(OldHeap, AccessExclusiveLock, false));
+ /* Determine the lock mode to use. */
+ lmode = RepackLockLevel(concurrent);
+
+ /*
+ * Check some preconditions in the concurrent case. This also obtains the
+ * replica index OID.
+ */
+ if (concurrent)
+ check_concurrent_repack_requirements(OldHeap, &ident_idx);
/* Check for user-requested abort. */
CHECK_FOR_INTERRUPTS();
RestrictSearchPath();
/*
- * Since we may open a new transaction for each relation, we have to check
- * that the relation still is what we think it is.
+ * Recheck that the relation is still what it was when we started.
*
- * If this is a single-transaction CLUSTER, we can skip these tests. We
- * *must* skip the one on indisclustered since it would reject an attempt
- * to cluster a not-previously-clustered index.
+ * Note that it's critical to skip this in single-relation CLUSTER;
+ * otherwise, we would reject an attempt to cluster using a
+ * not-previously-clustered index.
*/
if (recheck &&
!cluster_rel_recheck(cmd, OldHeap, indexOid, save_userid,
- params->options))
+ lmode, params->options))
goto out;
/*
errmsg("cannot execute %s on a shared catalog",
RepackCommandAsString(cmd)));
+ /*
+ * The CONCURRENTLY case should have been rejected earlier because it does
+ * not support system catalogs.
+ */
+ Assert(!(OldHeap->rd_rel->relisshared && concurrent));
+
/*
* Don't process temp tables of other backends ... their local buffer
* manager is not going to cope.
if (OidIsValid(indexOid))
{
/* verify the index is good and lock it */
- check_index_is_clusterable(OldHeap, indexOid, AccessExclusiveLock);
+ check_index_is_clusterable(OldHeap, indexOid, lmode);
/* also open it */
index = index_open(indexOid, NoLock);
}
if (OldHeap->rd_rel->relkind == RELKIND_MATVIEW &&
!RelationIsPopulated(OldHeap))
{
- relation_close(OldHeap, AccessExclusiveLock);
+ if (index)
+ index_close(index, lmode);
+ relation_close(OldHeap, lmode);
goto out;
}
* invalid, because we move tuples around. Promote them to relation
* locks. Predicate locks on indexes will be promoted when they are
* reindexed.
+ *
+ * During concurrent processing, the heap as well as its indexes stay in
+ * operation, so we postpone this step until they are locked using
+ * AccessExclusiveLock near the end of the processing.
*/
- TransferPredicateLocksToHeapRelation(OldHeap);
+ if (!concurrent)
+ TransferPredicateLocksToHeapRelation(OldHeap);
/* rebuild_relation does all the dirty work */
- rebuild_relation(OldHeap, index, verbose);
+ PG_TRY();
+ {
+ rebuild_relation(OldHeap, index, verbose, ident_idx);
+ }
+ PG_FINALLY();
+ {
+ if (concurrent)
+ {
+ /*
+ * Since during normal operation the worker was already asked to
+ * exit, stopping it explicitly is especially important on ERROR.
+ * However it still seems a good practice to make sure that the
+ * worker never survives the REPACK command.
+ */
+ stop_repack_decoding_worker();
+ }
+ }
+ PG_END_TRY();
+
/* rebuild_relation closes OldHeap, and index if valid */
out:
*/
static bool
cluster_rel_recheck(RepackCommand cmd, Relation OldHeap, Oid indexOid,
- Oid userid, int options)
+ Oid userid, LOCKMODE lmode, int options)
{
Oid tableOid = RelationGetRelid(OldHeap);
/* Check that the user still has privileges for the relation */
if (!repack_is_permitted_for_relation(cmd, tableOid, userid))
{
- relation_close(OldHeap, AccessExclusiveLock);
+ relation_close(OldHeap, lmode);
return false;
}
*/
if (RELATION_IS_OTHER_TEMP(OldHeap))
{
- relation_close(OldHeap, AccessExclusiveLock);
+ relation_close(OldHeap, lmode);
return false;
}
*/
if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(indexOid)))
{
- relation_close(OldHeap, AccessExclusiveLock);
+ relation_close(OldHeap, lmode);
return false;
}
if ((options & CLUOPT_RECHECK_ISCLUSTERED) != 0 &&
!get_index_isclustered(indexOid))
{
- relation_close(OldHeap, AccessExclusiveLock);
+ relation_close(OldHeap, lmode);
return false;
}
}
* Verify that the specified heap and index are valid to cluster on
*
* Side effect: obtains lock on the index. The caller may
- * in some cases already have AccessExclusiveLock on the table, but
+ * in some cases already have a lock of the same strength on the table, but
* not in all cases so we can't rely on the table-level lock for
* protection here.
*/
table_close(pg_index, RowExclusiveLock);
}
+/*
+ * Check if the CONCURRENTLY option is legal for the relation.
+ *
+ * *Ident_idx_p receives OID of the identity index.
+ */
+static void
+check_concurrent_repack_requirements(Relation rel, Oid *ident_idx_p)
+{
+ char relpersistence,
+ replident;
+ Oid ident_idx;
+
+ /* Data changes in system relations are not logically decoded. */
+ if (IsCatalogRelation(rel))
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot repack relation \"%s\"",
+ RelationGetRelationName(rel)),
+ errhint("REPACK CONCURRENTLY is not supported for catalog relations."));
+
+ /*
+ * reorderbuffer.c does not seem to handle processing of TOAST relation
+ * alone.
+ */
+ if (IsToastRelation(rel))
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("cannot repack relation \"%s\"",
+ RelationGetRelationName(rel)),
+ errhint("REPACK CONCURRENTLY is not supported for TOAST relations"));
+
+ relpersistence = rel->rd_rel->relpersistence;
+ if (relpersistence != RELPERSISTENCE_PERMANENT)
+ ereport(ERROR,
+ errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot repack relation \"%s\"",
+ RelationGetRelationName(rel)),
+ errhint("REPACK CONCURRENTLY is only allowed for permanent relations."));
+
+ /* With NOTHING, WAL does not contain the old tuple. */
+ replident = rel->rd_rel->relreplident;
+ if (replident == REPLICA_IDENTITY_NOTHING)
+ ereport(ERROR,
+ errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot repack relation \"%s\"",
+ RelationGetRelationName(rel)),
+ errhint("Relation \"%s\" has insufficient replication identity.",
+ RelationGetRelationName(rel)));
+
+ /*
+ * Obtain the replica identity index -- either one that has been set
+ * explicitly, or the primary key. If none of these cases apply, the
+ * table cannot be repacked concurrently. It might be possible to have
+ * repack work with a FULL replica identity; however that requires more
+ * work and is not implemented yet.
+ */
+ ident_idx = RelationGetReplicaIndex(rel);
+ if (!OidIsValid(ident_idx) && OidIsValid(rel->rd_pkindex))
+ ident_idx = rel->rd_pkindex;
+ if (!OidIsValid(ident_idx))
+ ereport(ERROR,
+ errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("cannot process relation \"%s\"",
+ RelationGetRelationName(rel)),
+ errhint("Relation \"%s\" has no identity index.",
+ RelationGetRelationName(rel)));
+
+ *ident_idx_p = ident_idx;
+}
+
+
/*
* rebuild_relation: rebuild an existing relation in index or physical order
*
- * OldHeap: table to rebuild.
+ * OldHeap: table to rebuild. See cluster_rel() for comments on the required
+ * lock strength.
+ *
* index: index to cluster by, or NULL to rewrite in physical order.
*
- * On entry, heap and index (if one is given) must be open, and
- * AccessExclusiveLock held on them.
- * On exit, they are closed, but locks on them are not released.
+ * ident_idx: identity index, to handle replaying of concurrent data changes
+ * to the new heap. InvalidOid if there's no CONCURRENTLY option.
+ *
+ * On entry, heap and index (if one is given) must be open, and the
+ * appropriate lock held on them -- AccessExclusiveLock for exclusive
+ * processing and ShareUpdateExclusiveLock for concurrent processing.
+ *
+ * On exit, they are closed, but still locked with AccessExclusiveLock.
+ * (The function handles the lock upgrade if 'concurrent' is true.)
*/
static void
-rebuild_relation(Relation OldHeap, Relation index, bool verbose)
+rebuild_relation(Relation OldHeap, Relation index, bool verbose,
+ Oid ident_idx)
{
Oid tableOid = RelationGetRelid(OldHeap);
Oid accessMethod = OldHeap->rd_rel->relam;
Oid OIDNewHeap;
Relation NewHeap;
char relpersistence;
- bool is_system_catalog;
bool swap_toast_by_content;
TransactionId frozenXid;
MultiXactId cutoffMulti;
+ bool concurrent = OidIsValid(ident_idx);
+ Snapshot snapshot = NULL;
+#if USE_ASSERT_CHECKING
+ LOCKMODE lmode;
+
+ lmode = RepackLockLevel(concurrent);
+
+ Assert(CheckRelationLockedByMe(OldHeap, lmode, false));
+ Assert(index == NULL || CheckRelationLockedByMe(index, lmode, false));
+#endif
+
+ if (concurrent)
+ {
+ /*
+ * The worker needs to be member of the locking group we're the leader
+ * of. We ought to become the leader before the worker starts. The
+ * worker will join the group as soon as it starts.
+ *
+ * This is to make sure that the deadlock described below is
+ * detectable by deadlock.c: if the worker waits for a transaction to
+ * complete and we are waiting for the worker output, then effectively
+ * we (i.e. this backend) are waiting for that transaction.
+ */
+ BecomeLockGroupLeader();
+
+ /*
+ * Start the worker that decodes data changes applied while we're
+ * copying the table contents.
+ *
+ * Note that the worker has to wait for all transactions with XID
+ * already assigned to finish. If some of those transactions is
+ * waiting for a lock conflicting with ShareUpdateExclusiveLock on our
+ * table (e.g. it runs CREATE INDEX), we can end up in a deadlock.
+ * Not sure this risk is worth unlocking/locking the table (and its
+ * clustering index) and checking again if it's still eligible for
+ * REPACK CONCURRENTLY.
+ */
+ start_repack_decoding_worker(tableOid);
+
+ /*
+ * Wait until the worker has the initial snapshot and retrieve it.
+ */
+ snapshot = get_initial_snapshot(decoding_worker);
- Assert(CheckRelationLockedByMe(OldHeap, AccessExclusiveLock, false) &&
- (index == NULL || CheckRelationLockedByMe(index, AccessExclusiveLock, false)));
+ PushActiveSnapshot(snapshot);
+ }
/* for CLUSTER or REPACK USING INDEX, mark the index as the one to use */
if (index != NULL)
/* Remember info about rel before closing OldHeap */
relpersistence = OldHeap->rd_rel->relpersistence;
- is_system_catalog = IsSystemRelation(OldHeap);
/*
* Create the transient table that will receive the re-ordered data.
NewHeap = table_open(OIDNewHeap, NoLock);
/* Copy the heap data into the new table in the desired order */
- copy_table_data(NewHeap, OldHeap, index, verbose,
+ copy_table_data(NewHeap, OldHeap, index, snapshot, verbose,
&swap_toast_by_content, &frozenXid, &cutoffMulti);
+ /* The historic snapshot won't be needed anymore. */
+ if (snapshot)
+ {
+ PopActiveSnapshot();
+ UpdateActiveSnapshotCommandId();
+ }
- /* Close relcache entries, but keep lock until transaction commit */
- table_close(OldHeap, NoLock);
- if (index)
- index_close(index, NoLock);
+ if (concurrent)
+ {
+ Assert(!swap_toast_by_content);
- /*
- * Close the new relation so it can be dropped as soon as the storage is
- * swapped. The relation is not visible to others, so no need to unlock it
- * explicitly.
- */
- table_close(NewHeap, NoLock);
+ /*
+ * Close the index, but keep the lock. Both heaps will be closed by
+ * the following call.
+ */
+ if (index)
+ index_close(index, NoLock);
- /*
- * Swap the physical files of the target and transient tables, then
- * rebuild the target's indexes and throw away the transient table.
- */
- finish_heap_swap(tableOid, OIDNewHeap, is_system_catalog,
- swap_toast_by_content, false, true,
- frozenXid, cutoffMulti,
- relpersistence);
+ rebuild_relation_finish_concurrent(NewHeap, OldHeap, ident_idx,
+ frozenXid, cutoffMulti);
+
+ pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
+ PROGRESS_REPACK_PHASE_FINAL_CLEANUP);
+ }
+ else
+ {
+ bool is_system_catalog = IsSystemRelation(OldHeap);
+
+ /* Close relcache entries, but keep lock until transaction commit */
+ table_close(OldHeap, NoLock);
+ if (index)
+ index_close(index, NoLock);
+
+ /*
+ * Close the new relation so it can be dropped as soon as the storage
+ * is swapped. The relation is not visible to others, so no need to
+ * unlock it explicitly.
+ */
+ table_close(NewHeap, NoLock);
+
+ /*
+ * Swap the physical files of the target and transient tables, then
+ * rebuild the target's indexes and throw away the transient table.
+ */
+ finish_heap_swap(tableOid, OIDNewHeap, is_system_catalog,
+ swap_toast_by_content, false, true,
+ true, /* reindex */
+ frozenXid, cutoffMulti,
+ relpersistence);
+ }
}
/*
* Do the physical copying of table data.
*
+ * 'snapshot' and 'decoding_ctx': see table_relation_copy_for_cluster(). Pass
+ * iff concurrent processing is required.
+ *
* There are three output parameters:
* *pSwapToastByContent is set true if toast tables must be swapped by content.
* *pFreezeXid receives the TransactionId used as freeze cutoff point.
* *pCutoffMulti receives the MultiXactId used as a cutoff point.
*/
static void
-copy_table_data(Relation NewHeap, Relation OldHeap, Relation OldIndex, bool verbose,
- bool *pSwapToastByContent, TransactionId *pFreezeXid,
- MultiXactId *pCutoffMulti)
+copy_table_data(Relation NewHeap, Relation OldHeap, Relation OldIndex,
+ Snapshot snapshot, bool verbose, bool *pSwapToastByContent,
+ TransactionId *pFreezeXid, MultiXactId *pCutoffMulti)
{
Relation relRelation;
HeapTuple reltup;
int elevel = verbose ? INFO : DEBUG2;
PGRUsage ru0;
char *nspname;
+ bool concurrent = snapshot != NULL;
+ LOCKMODE lmode;
+
+ lmode = RepackLockLevel(concurrent);
pg_rusage_init(&ru0);
* will be held till end of transaction.
*/
if (OldHeap->rd_rel->reltoastrelid)
- LockRelationOid(OldHeap->rd_rel->reltoastrelid, AccessExclusiveLock);
+ LockRelationOid(OldHeap->rd_rel->reltoastrelid, lmode);
/*
* If both tables have TOAST tables, perform toast swap by content. It is
* swap by links. This is okay because swap by content is only essential
* for system catalogs, and we don't support schema changes for them.
*/
- if (OldHeap->rd_rel->reltoastrelid && NewHeap->rd_rel->reltoastrelid)
+ if (OldHeap->rd_rel->reltoastrelid && NewHeap->rd_rel->reltoastrelid &&
+ !concurrent)
{
*pSwapToastByContent = true;
* follow the toast pointers to the wrong place. (It would actually
* work for values copied over from the old toast table, but not for
* any values that we toast which were previously not toasted.)
+ *
+ * This would not work with CONCURRENTLY because we may need to delete
+ * TOASTed tuples from the new heap. With this hack, we'd delete them
+ * from the old heap.
*/
NewHeap->rd_toastoid = OldHeap->rd_rel->reltoastrelid;
}
* values (e.g. because the AM doesn't use freezing).
*/
table_relation_copy_for_cluster(OldHeap, NewHeap, OldIndex, use_sort,
- cutoffs.OldestXmin, &cutoffs.FreezeLimit,
+ cutoffs.OldestXmin, snapshot,
+ &cutoffs.FreezeLimit,
&cutoffs.MultiXactCutoff,
&num_tuples, &tups_vacuumed,
&tups_recently_dead);
*pFreezeXid = cutoffs.FreezeLimit;
*pCutoffMulti = cutoffs.MultiXactCutoff;
- /* Reset rd_toastoid just to be tidy --- it shouldn't be looked at again */
+ /*
+ * Reset rd_toastoid just to be tidy --- it shouldn't be looked at again.
+ * In the CONCURRENTLY case, we need to set it again before applying the
+ * concurrent changes.
+ */
NewHeap->rd_toastoid = InvalidOid;
num_pages = RelationGetNumberOfBlocks(NewHeap);
bool swap_toast_by_content,
bool check_constraints,
bool is_internal,
+ bool reindex,
TransactionId frozenXid,
MultiXactId cutoffMulti,
char newrelpersistence)
{
ObjectAddress object;
Oid mapped_tables[4];
- int reindex_flags;
- ReindexParams reindex_params = {0};
int i;
/* Report that we are now swapping relation files */
if (is_system_catalog)
CacheInvalidateCatalog(OIDOldHeap);
- /*
- * Rebuild each index on the relation (but not the toast table, which is
- * all-new at this point). It is important to do this before the DROP
- * step because if we are processing a system catalog that will be used
- * during DROP, we want to have its indexes available. There is no
- * advantage to the other order anyway because this is all transactional,
- * so no chance to reclaim disk space before commit. We do not need a
- * final CommandCounterIncrement() because reindex_relation does it.
- *
- * Note: because index_build is called via reindex_relation, it will never
- * set indcheckxmin true for the indexes. This is OK even though in some
- * sense we are building new indexes rather than rebuilding existing ones,
- * because the new heap won't contain any HOT chains at all, let alone
- * broken ones, so it can't be necessary to set indcheckxmin.
- */
- reindex_flags = REINDEX_REL_SUPPRESS_INDEX_USE;
- if (check_constraints)
- reindex_flags |= REINDEX_REL_CHECK_CONSTRAINTS;
+ if (reindex)
+ {
+ int reindex_flags;
+ ReindexParams reindex_params = {0};
- /*
- * Ensure that the indexes have the same persistence as the parent
- * relation.
- */
- if (newrelpersistence == RELPERSISTENCE_UNLOGGED)
- reindex_flags |= REINDEX_REL_FORCE_INDEXES_UNLOGGED;
- else if (newrelpersistence == RELPERSISTENCE_PERMANENT)
- reindex_flags |= REINDEX_REL_FORCE_INDEXES_PERMANENT;
+ /*
+ * Rebuild each index on the relation (but not the toast table, which
+ * is all-new at this point). It is important to do this before the
+ * DROP step because if we are processing a system catalog that will
+ * be used during DROP, we want to have its indexes available. There
+ * is no advantage to the other order anyway because this is all
+ * transactional, so no chance to reclaim disk space before commit. We
+ * do not need a final CommandCounterIncrement() because
+ * reindex_relation does it.
+ *
+ * Note: because index_build is called via reindex_relation, it will
+ * never set indcheckxmin true for the indexes. This is OK even
+ * though in some sense we are building new indexes rather than
+ * rebuilding existing ones, because the new heap won't contain any
+ * HOT chains at all, let alone broken ones, so it can't be necessary
+ * to set indcheckxmin.
+ */
+ reindex_flags = REINDEX_REL_SUPPRESS_INDEX_USE;
+ if (check_constraints)
+ reindex_flags |= REINDEX_REL_CHECK_CONSTRAINTS;
- /* Report that we are now reindexing relations */
- pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
- PROGRESS_REPACK_PHASE_REBUILD_INDEX);
+ /*
+ * Ensure that the indexes have the same persistence as the parent
+ * relation.
+ */
+ if (newrelpersistence == RELPERSISTENCE_UNLOGGED)
+ reindex_flags |= REINDEX_REL_FORCE_INDEXES_UNLOGGED;
+ else if (newrelpersistence == RELPERSISTENCE_PERMANENT)
+ reindex_flags |= REINDEX_REL_FORCE_INDEXES_PERMANENT;
- reindex_relation(NULL, OIDOldHeap, reindex_flags, &reindex_params);
+ /* Report that we are now reindexing relations */
+ pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
+ PROGRESS_REPACK_PHASE_REBUILD_INDEX);
+
+ reindex_relation(NULL, OIDOldHeap, reindex_flags, &reindex_params);
+ }
/* Report that we are now doing clean up */
pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
object.objectId = OIDNewHeap;
object.objectSubId = 0;
+ if (!reindex)
+ {
+ /*
+ * Make sure the changes in pg_class are visible. This is especially
+ * important if !swap_toast_by_content, so that the correct TOAST
+ * relation is dropped. (reindex_relation() above did not help in this
+ * case))
+ */
+ CommandCounterIncrement();
+ }
+
/*
* The new relation is local to our transaction and we know nothing
* depends on it, so DROP_RESTRICT should be OK.
/* Get the associated valid index to be renamed */
toastidx = toast_get_valid_index(newrel->rd_rel->reltoastrelid,
- NoLock);
+ AccessExclusiveLock);
/* rename the toast table ... */
snprintf(NewToastName, NAMEDATALEN, "pg_toast_%u",
* case, if an index name is given, it's up to the caller to resolve it.
*/
static Relation
-process_single_relation(RepackStmt *stmt, ClusterParams *params)
+process_single_relation(RepackStmt *stmt, LOCKMODE lockmode, bool isTopLevel,
+ ClusterParams *params)
{
Relation rel;
Oid tableOid;
errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("ANALYZE option must be specified when a column list is provided"));
- /*
- * Find, lock, and check permissions on the table. We obtain
- * AccessExclusiveLock right away to avoid lock-upgrade hazard in the
- * single-transaction case.
- */
+ /* Find, lock, and check permissions on the table. */
tableOid = RangeVarGetRelidExtended(stmt->relation->relation,
- AccessExclusiveLock,
+ lockmode,
0,
RangeVarCallbackMaintainsTable,
NULL);
return rel;
else
{
- Oid indexOid;
+ Oid indexOid = InvalidOid;
indexOid = determine_clustered_index(rel, stmt->usingindex,
stmt->indexname);
if (OidIsValid(indexOid))
- check_index_is_clusterable(rel, indexOid, AccessExclusiveLock);
- cluster_rel(stmt->command, rel, indexOid, params);
+ check_index_is_clusterable(rel, indexOid, lockmode);
+
+ cluster_rel(stmt->command, rel, indexOid, params, isTopLevel);
/*
* Do an analyze, if requested. We close the transaction and start a
}
return "???"; /* keep compiler quiet */
}
+
+/*
+ * Apply all the changes stored in 'file'.
+ */
+static void
+apply_concurrent_changes(BufFile *file, ChangeContext *chgcxt)
+{
+ ConcurrentChangeKind kind = '\0';
+ Relation rel = chgcxt->cc_rel;
+ TupleTableSlot *spilled_tuple;
+ TupleTableSlot *old_update_tuple;
+ TupleTableSlot *ondisk_tuple;
+ bool have_old_tuple = false;
+ MemoryContext oldcxt;
+
+ spilled_tuple = MakeSingleTupleTableSlot(RelationGetDescr(rel),
+ &TTSOpsVirtual);
+ ondisk_tuple = MakeSingleTupleTableSlot(RelationGetDescr(rel),
+ table_slot_callbacks(rel));
+ old_update_tuple = MakeSingleTupleTableSlot(RelationGetDescr(rel),
+ &TTSOpsVirtual);
+
+ oldcxt = MemoryContextSwitchTo(GetPerTupleMemoryContext(chgcxt->cc_estate));
+
+ while (true)
+ {
+ size_t nread;
+ ConcurrentChangeKind prevkind = kind;
+
+ CHECK_FOR_INTERRUPTS();
+
+ nread = BufFileReadMaybeEOF(file, &kind, 1, true);
+ if (nread == 0) /* done with the file? */
+ break;
+
+ /*
+ * If this is the old tuple for an update, read it into the tuple slot
+ * and go to the next one. The update itself will be executed on the
+ * next iteration, when we receive the NEW tuple.
+ */
+ if (kind == CHANGE_UPDATE_OLD)
+ {
+ restore_tuple(file, rel, old_update_tuple);
+ have_old_tuple = true;
+ continue;
+ }
+
+ /*
+ * Just before an UPDATE or DELETE, we must update the command
+ * counter, because the change could refer to a tuple that we have
+ * just inserted; and before an INSERT, we have to do this also if the
+ * previous command was either update or delete.
+ *
+ * With this approach we don't spend so many CCIs for long strings of
+ * only INSERTs, which can't affect one another.
+ */
+ if (kind == CHANGE_UPDATE_NEW || kind == CHANGE_DELETE ||
+ (kind == CHANGE_INSERT && (prevkind == CHANGE_UPDATE_NEW ||
+ prevkind == CHANGE_DELETE)))
+ {
+ CommandCounterIncrement();
+ UpdateActiveSnapshotCommandId();
+ }
+
+ /*
+ * Now restore the tuple into the slot and execute the change.
+ */
+ restore_tuple(file, rel, spilled_tuple);
+
+ if (kind == CHANGE_INSERT)
+ {
+ apply_concurrent_insert(rel, spilled_tuple, chgcxt);
+ }
+ else if (kind == CHANGE_DELETE)
+ {
+ bool found;
+
+ /* Find the tuple to be deleted */
+ found = find_target_tuple(rel, chgcxt, spilled_tuple, ondisk_tuple);
+ if (!found)
+ elog(ERROR, "failed to find target tuple");
+ apply_concurrent_delete(rel, ondisk_tuple);
+ }
+ else if (kind == CHANGE_UPDATE_NEW)
+ {
+ TupleTableSlot *key;
+ bool found;
+
+ if (have_old_tuple)
+ key = old_update_tuple;
+ else
+ key = spilled_tuple;
+
+ /* Find the tuple to be updated or deleted. */
+ found = find_target_tuple(rel, chgcxt, key, ondisk_tuple);
+ if (!found)
+ elog(ERROR, "failed to find target tuple");
+
+ /*
+ * If 'tup' contains TOAST pointers, they point to the old
+ * relation's toast. Copy the corresponding TOAST pointers for the
+ * new relation from the existing tuple. (The fact that we
+ * received a TOAST pointer here implies that the attribute hasn't
+ * changed.)
+ */
+ adjust_toast_pointers(rel, spilled_tuple, ondisk_tuple);
+
+ apply_concurrent_update(rel, spilled_tuple, ondisk_tuple, chgcxt);
+
+ ExecClearTuple(old_update_tuple);
+ have_old_tuple = false;
+ }
+ else
+ elog(ERROR, "unrecognized kind of change: %d", kind);
+
+ ResetPerTupleExprContext(chgcxt->cc_estate);
+ }
+
+ /* Cleanup. */
+ ExecDropSingleTupleTableSlot(spilled_tuple);
+ ExecDropSingleTupleTableSlot(ondisk_tuple);
+ ExecDropSingleTupleTableSlot(old_update_tuple);
+
+ MemoryContextSwitchTo(oldcxt);
+}
+
+/*
+ * Apply an insert from the spill of concurrent changes to the new copy of the
+ * table.
+ */
+static void
+apply_concurrent_insert(Relation rel, TupleTableSlot *slot,
+ ChangeContext *chgcxt)
+{
+ /* Put the tuple in the table, but make sure it won't be decoded */
+ table_tuple_insert(rel, slot, GetCurrentCommandId(true),
+ TABLE_INSERT_NO_LOGICAL, NULL);
+
+ /* Update indexes with this new tuple. */
+ ExecInsertIndexTuples(chgcxt->cc_rri,
+ chgcxt->cc_estate,
+ 0,
+ slot,
+ NIL, NULL);
+ pgstat_progress_incr_param(PROGRESS_REPACK_HEAP_TUPLES_INSERTED, 1);
+}
+
+/*
+ * Apply an update from the spill of concurrent changes to the new copy of the
+ * table.
+ */
+static void
+apply_concurrent_update(Relation rel, TupleTableSlot *spilled_tuple,
+ TupleTableSlot *ondisk_tuple,
+ ChangeContext *chgcxt)
+{
+ LockTupleMode lockmode;
+ TM_FailureData tmfd;
+ TU_UpdateIndexes update_indexes;
+ TM_Result res;
+
+ /*
+ * Carry out the update, skipping logical decoding for it.
+ */
+ res = table_tuple_update(rel, &(ondisk_tuple->tts_tid), spilled_tuple,
+ GetCurrentCommandId(true),
+ TABLE_UPDATE_NO_LOGICAL,
+ InvalidSnapshot,
+ InvalidSnapshot,
+ false,
+ &tmfd, &lockmode, &update_indexes);
+ if (res != TM_Ok)
+ ereport(ERROR,
+ errmsg("failed to apply concurrent UPDATE"));
+
+ if (update_indexes != TU_None)
+ {
+ uint32 flags = EIIT_IS_UPDATE;
+
+ if (update_indexes == TU_Summarizing)
+ flags |= EIIT_ONLY_SUMMARIZING;
+ ExecInsertIndexTuples(chgcxt->cc_rri,
+ chgcxt->cc_estate,
+ flags,
+ spilled_tuple,
+ NIL, NULL);
+ }
+
+ pgstat_progress_incr_param(PROGRESS_REPACK_HEAP_TUPLES_UPDATED, 1);
+}
+
+static void
+apply_concurrent_delete(Relation rel, TupleTableSlot *slot)
+{
+ TM_Result res;
+ TM_FailureData tmfd;
+
+ /*
+ * Delete tuple from the new heap, skipping logical decoding for it.
+ */
+ res = table_tuple_delete(rel, &(slot->tts_tid),
+ GetCurrentCommandId(true),
+ TABLE_DELETE_NO_LOGICAL,
+ InvalidSnapshot, InvalidSnapshot,
+ false,
+ &tmfd);
+
+ if (res != TM_Ok)
+ ereport(ERROR,
+ errmsg("failed to apply concurrent DELETE"));
+
+ pgstat_progress_incr_param(PROGRESS_REPACK_HEAP_TUPLES_DELETED, 1);
+}
+
+/*
+ * Read tuple from file and put it in the input slot. All memory is allocated
+ * in the current memory context; caller is responsible for freeing it as
+ * appropriate.
+ *
+ * External attributes are stored in separate memory chunks, in order to avoid
+ * exceeding MaxAllocSize - that could happen if the individual attributes are
+ * smaller than MaxAllocSize but the whole tuple is bigger.
+ */
+static void
+restore_tuple(BufFile *file, Relation relation, TupleTableSlot *slot)
+{
+ uint32 t_len;
+ HeapTuple tup;
+ int natt_ext;
+
+ /* Read the tuple. */
+ BufFileReadExact(file, &t_len, sizeof(t_len));
+ tup = (HeapTuple) palloc(HEAPTUPLESIZE + t_len);
+ tup->t_data = (HeapTupleHeader) ((char *) tup + HEAPTUPLESIZE);
+ BufFileReadExact(file, tup->t_data, t_len);
+ tup->t_len = t_len;
+ ItemPointerSetInvalid(&tup->t_self);
+ tup->t_tableOid = RelationGetRelid(relation);
+
+ /*
+ * Put the tuple we read in a slot. This deforms it, so that we can hack
+ * the external attributes in place.
+ */
+ ExecForceStoreHeapTuple(tup, slot, false);
+
+ /*
+ * Next, read any attributes we stored separately into the tts_values
+ * array elements expecting them, if any. This matches
+ * repack_store_change.
+ */
+ BufFileReadExact(file, &natt_ext, sizeof(natt_ext));
+ if (natt_ext > 0)
+ {
+ TupleDesc desc = slot->tts_tupleDescriptor;
+
+ for (int i = 0; i < desc->natts; i++)
+ {
+ CompactAttribute *attr = TupleDescCompactAttr(desc, i);
+ varlena *varlen;
+ union
+ {
+ alignas(int32) varlena hdr;
+ char data[sizeof(void *)];
+ } chunk_header;
+ void *value;
+ Size varlensz;
+
+ if (attr->attisdropped || attr->attlen != -1)
+ continue;
+ if (slot_attisnull(slot, i + 1))
+ continue;
+ varlen = (varlena *) DatumGetPointer(slot->tts_values[i]);
+ if (!VARATT_IS_EXTERNAL_INDIRECT(varlen))
+ continue;
+ slot_getsomeattrs(slot, i + 1);
+
+ BufFileReadExact(file, &chunk_header, VARHDRSZ);
+ varlensz = VARSIZE_ANY(&chunk_header);
+
+ value = palloc(varlensz);
+ SET_VARSIZE(value, VARSIZE_ANY(&chunk_header));
+ BufFileReadExact(file, (char *) value + VARHDRSZ, varlensz - VARHDRSZ);
+
+ slot->tts_values[i] = PointerGetDatum(value);
+ natt_ext--;
+ if (natt_ext < 0)
+ ereport(ERROR,
+ errcode(ERRCODE_DATA_CORRUPTED),
+ errmsg("insufficient number of attributes stored separately"));
+ }
+ }
+}
+
+/*
+ * Adjust 'dest' replacing any EXTERNAL_ONDISK toast pointers with the
+ * corresponding ones from 'src'.
+ */
+static void
+adjust_toast_pointers(Relation relation, TupleTableSlot *dest, TupleTableSlot *src)
+{
+ TupleDesc desc = dest->tts_tupleDescriptor;
+
+ for (int i = 0; i < desc->natts; i++)
+ {
+ CompactAttribute *attr = TupleDescCompactAttr(desc, i);
+ varlena *varlena_dst;
+
+ if (attr->attisdropped)
+ continue;
+ if (attr->attlen != -1)
+ continue;
+ if (slot_attisnull(dest, i + 1))
+ continue;
+
+ slot_getsomeattrs(dest, i + 1);
+
+ varlena_dst = (varlena *) DatumGetPointer(dest->tts_values[i]);
+ if (!VARATT_IS_EXTERNAL_ONDISK(varlena_dst))
+ continue;
+ slot_getsomeattrs(src, i + 1);
+
+ dest->tts_values[i] = src->tts_values[i];
+ }
+}
+
+/*
+ * Find the tuple to be updated or deleted by the given data change, whose
+ * tuple has already been loaded into locator.
+ *
+ * If the tuple is found, put it in retrieved and return true. If the tuple is
+ * not found, return false.
+ */
+static bool
+find_target_tuple(Relation rel, ChangeContext *chgcxt, TupleTableSlot *locator,
+ TupleTableSlot *retrieved)
+{
+ Form_pg_index idx = chgcxt->cc_ident_index->rd_index;
+ IndexScanDesc scan;
+ bool retval;
+
+ /*
+ * Scan key is passed by caller, so it does not have to be constructed
+ * multiple times. Key entries have all fields initialized, except for
+ * sk_argument.
+ *
+ * Use the incoming tuple to finalize the scan key.
+ */
+ for (int i = 0; i < chgcxt->cc_ident_key_nentries; i++)
+ {
+ ScanKey entry = &chgcxt->cc_ident_key[i];
+ AttrNumber attno = idx->indkey.values[i];
+
+ entry->sk_argument = locator->tts_values[attno - 1];
+ Assert(!locator->tts_isnull[attno - 1]);
+ }
+
+ /* XXX no instrumentation for now */
+ scan = index_beginscan(rel, chgcxt->cc_ident_index, GetActiveSnapshot(),
+ NULL, chgcxt->cc_ident_key_nentries, 0, 0);
+ index_rescan(scan, chgcxt->cc_ident_key, chgcxt->cc_ident_key_nentries, NULL, 0);
+ retval = index_getnext_slot(scan, ForwardScanDirection, retrieved);
+ index_endscan(scan);
+
+ return retval;
+}
+
+/*
+ * Decode and apply concurrent changes, up to (and including) the record whose
+ * LSN is 'end_of_wal'.
+ *
+ * XXX the names "process_concurrent_changes" and "apply_concurrent_changes"
+ * are far too similar to each other.
+ */
+static void
+process_concurrent_changes(XLogRecPtr end_of_wal, ChangeContext *chgcxt, bool done)
+{
+ DecodingWorkerShared *shared;
+ char fname[MAXPGPATH];
+ BufFile *file;
+
+ pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
+ PROGRESS_REPACK_PHASE_CATCH_UP);
+
+ /* Ask the worker for the file. */
+ shared = (DecodingWorkerShared *) dsm_segment_address(decoding_worker->seg);
+ SpinLockAcquire(&shared->mutex);
+ shared->lsn_upto = end_of_wal;
+ shared->done = done;
+ SpinLockRelease(&shared->mutex);
+
+ /*
+ * The worker needs to finish processing of the current WAL record. Even
+ * if it's idle, it'll need to close the output file. Thus we're likely to
+ * wait, so prepare for sleep.
+ */
+ ConditionVariablePrepareToSleep(&shared->cv);
+ for (;;)
+ {
+ int last_exported;
+
+ SpinLockAcquire(&shared->mutex);
+ last_exported = shared->last_exported;
+ SpinLockRelease(&shared->mutex);
+
+ /*
+ * Has the worker exported the file we are waiting for?
+ */
+ if (last_exported == chgcxt->cc_file_seq)
+ break;
+
+ ConditionVariableSleep(&shared->cv, WAIT_EVENT_REPACK_WORKER_EXPORT);
+ }
+ ConditionVariableCancelSleep();
+
+ /* Open the file. */
+ DecodingWorkerFileName(fname, shared->relid, chgcxt->cc_file_seq);
+ file = BufFileOpenFileSet(&shared->sfs.fs, fname, O_RDONLY, false);
+ apply_concurrent_changes(file, chgcxt);
+
+ BufFileClose(file);
+
+ /* Get ready for the next file. */
+ chgcxt->cc_file_seq++;
+}
+
+/*
+ * Initialize the ChangeContext struct for the given relation, with
+ * the given index as identity index.
+ */
+static void
+initialize_change_context(ChangeContext *chgcxt,
+ Relation relation, Oid ident_index_id)
+{
+ chgcxt->cc_rel = relation;
+
+ /* Only initialize fields needed by ExecInsertIndexTuples(). */
+ chgcxt->cc_estate = CreateExecutorState();
+
+ chgcxt->cc_rri = (ResultRelInfo *) palloc(sizeof(ResultRelInfo));
+ InitResultRelInfo(chgcxt->cc_rri, relation, 0, 0, 0);
+ ExecOpenIndices(chgcxt->cc_rri, false);
+
+ /*
+ * The table's relcache entry already has the relcache entry for the
+ * identity index; find that.
+ */
+ chgcxt->cc_ident_index = NULL;
+ for (int i = 0; i < chgcxt->cc_rri->ri_NumIndices; i++)
+ {
+ Relation ind_rel;
+
+ ind_rel = chgcxt->cc_rri->ri_IndexRelationDescs[i];
+ if (ind_rel->rd_id == ident_index_id)
+ {
+ chgcxt->cc_ident_index = ind_rel;
+ break;
+ }
+ }
+ if (chgcxt->cc_ident_index == NULL)
+ elog(ERROR, "failed to find identity index");
+
+ /* Set up for scanning said identity index */
+ {
+ Form_pg_index indexForm;
+
+ indexForm = chgcxt->cc_ident_index->rd_index;
+ chgcxt->cc_ident_key_nentries = indexForm->indnkeyatts;
+ chgcxt->cc_ident_key = (ScanKey) palloc_array(ScanKeyData, indexForm->indnkeyatts);
+ for (int i = 0; i < indexForm->indnkeyatts; i++)
+ {
+ ScanKey entry;
+ Oid opfamily,
+ opcintype,
+ opno,
+ opcode;
+
+ entry = &chgcxt->cc_ident_key[i];
+
+ opfamily = chgcxt->cc_ident_index->rd_opfamily[i];
+ opcintype = chgcxt->cc_ident_index->rd_opcintype[i];
+ opno = get_opfamily_member(opfamily, opcintype, opcintype,
+ BTEqualStrategyNumber);
+ if (!OidIsValid(opno))
+ elog(ERROR, "failed to find = operator for type %u", opcintype);
+ opcode = get_opcode(opno);
+ if (!OidIsValid(opcode))
+ elog(ERROR, "failed to find = operator for operator %u", opno);
+
+ /* Initialize everything but argument. */
+ ScanKeyInit(entry,
+ i + 1,
+ BTEqualStrategyNumber, opcode,
+ (Datum) NULL);
+ entry->sk_collation = chgcxt->cc_ident_index->rd_indcollation[i];
+ }
+ }
+
+ chgcxt->cc_file_seq = WORKER_FILE_SNAPSHOT + 1;
+}
+
+/*
+ * Free up resources taken by a ChangeContext.
+ */
+static void
+release_change_context(ChangeContext *chgcxt)
+{
+ ExecCloseIndices(chgcxt->cc_rri);
+ FreeExecutorState(chgcxt->cc_estate);
+ /* XXX are these pfrees necessary? */
+ pfree(chgcxt->cc_rri);
+ pfree(chgcxt->cc_ident_key);
+}
+
+/*
+ * The final steps of rebuild_relation() for concurrent processing.
+ *
+ * On entry, NewHeap is locked in AccessExclusiveLock mode. OldHeap and its
+ * clustering index (if one is passed) are still locked in a mode that allows
+ * concurrent data changes. On exit, both tables and their indexes are closed,
+ * but locked in AccessExclusiveLock mode.
+ */
+static void
+rebuild_relation_finish_concurrent(Relation NewHeap, Relation OldHeap,
+ Oid identIdx, TransactionId frozenXid,
+ MultiXactId cutoffMulti)
+{
+ List *ind_oids_new;
+ Oid old_table_oid = RelationGetRelid(OldHeap);
+ Oid new_table_oid = RelationGetRelid(NewHeap);
+ List *ind_oids_old = RelationGetIndexList(OldHeap);
+ ListCell *lc,
+ *lc2;
+ char relpersistence;
+ bool is_system_catalog;
+ Oid ident_idx_new;
+ XLogRecPtr end_of_wal;
+ List *indexrels;
+ ChangeContext chgcxt;
+
+ Assert(CheckRelationLockedByMe(OldHeap, ShareUpdateExclusiveLock, false));
+ Assert(CheckRelationLockedByMe(NewHeap, AccessExclusiveLock, false));
+
+ /*
+ * Unlike the exclusive case, we build new indexes for the new relation
+ * rather than swapping the storage and reindexing the old relation. The
+ * point is that the index build can take some time, so we do it before we
+ * get AccessExclusiveLock on the old heap and therefore we cannot swap
+ * the heap storage yet.
+ *
+ * index_create() will lock the new indexes using AccessExclusiveLock - no
+ * need to change that. At the same time, we use ShareUpdateExclusiveLock
+ * to lock the existing indexes - that should be enough to prevent others
+ * from changing them while we're repacking the relation. The lock on
+ * table should prevent others from changing the index column list, but
+ * might not be enough for commands like ALTER INDEX ... SET ... (Those
+ * are not necessarily dangerous, but can make user confused if the
+ * changes they do get lost due to REPACK.)
+ */
+ ind_oids_new = build_new_indexes(NewHeap, OldHeap, ind_oids_old);
+
+ /*
+ * The identity index in the new relation appears in the same relative
+ * position as the corresponding index in the old relation. Find it.
+ */
+ ident_idx_new = InvalidOid;
+ foreach_oid(ind_old, ind_oids_old)
+ {
+ if (identIdx == ind_old)
+ {
+ int pos = foreach_current_index(ind_old);
+
+ if (unlikely(list_length(ind_oids_new) < pos))
+ elog(ERROR, "list of new indexes too short");
+ ident_idx_new = list_nth_oid(ind_oids_new, pos);
+ break;
+ }
+ }
+ if (!OidIsValid(ident_idx_new))
+ elog(ERROR, "could not find index matching \"%s\" at the new relation",
+ get_rel_name(identIdx));
+
+ /* Gather information to apply concurrent changes. */
+ initialize_change_context(&chgcxt, NewHeap, ident_idx_new);
+
+ /*
+ * During testing, wait for another backend to perform concurrent data
+ * changes which we will process below.
+ */
+ INJECTION_POINT("repack-concurrently-before-lock", NULL);
+
+ /*
+ * Flush all WAL records inserted so far (possibly except for the last
+ * incomplete page; see GetInsertRecPtr), to minimize the amount of data
+ * we need to flush while holding exclusive lock on the source table.
+ */
+ XLogFlush(GetXLogInsertEndRecPtr());
+ end_of_wal = GetFlushRecPtr(NULL);
+
+ /*
+ * Apply concurrent changes first time, to minimize the time we need to
+ * hold AccessExclusiveLock. (Quite some amount of WAL could have been
+ * written during the data copying and index creation.)
+ */
+ process_concurrent_changes(end_of_wal, &chgcxt, false);
+
+ /*
+ * Acquire AccessExclusiveLock on the table, its TOAST relation (if there
+ * is one), all its indexes, so that we can swap the files.
+ */
+ LockRelationOid(old_table_oid, AccessExclusiveLock);
+
+ /*
+ * Lock all indexes now, not only the clustering one: all indexes need to
+ * have their files swapped. While doing that, store their relation
+ * references in a zero-terminated array, to handle predicate locks below.
+ */
+ indexrels = NIL;
+ foreach_oid(ind_oid, ind_oids_old)
+ {
+ Relation index;
+
+ index = index_open(ind_oid, AccessExclusiveLock);
+
+ /*
+ * Some things about the index may have changed before we locked the
+ * index, such as ALTER INDEX RENAME. We don't need to do anything
+ * here to absorb those changes in the new index.
+ */
+ indexrels = lappend(indexrels, index);
+ }
+
+ /*
+ * Lock the OldHeap's TOAST relation exclusively - again, the lock is
+ * needed to swap the files.
+ */
+ if (OidIsValid(OldHeap->rd_rel->reltoastrelid))
+ LockRelationOid(OldHeap->rd_rel->reltoastrelid, AccessExclusiveLock);
+
+ /*
+ * Tuples and pages of the old heap will be gone, but the heap will stay.
+ */
+ TransferPredicateLocksToHeapRelation(OldHeap);
+ foreach_ptr(RelationData, index, indexrels)
+ {
+ TransferPredicateLocksToHeapRelation(index);
+ index_close(index, NoLock);
+ }
+ list_free(indexrels);
+
+ /*
+ * Flush WAL again, to make sure that all changes committed while we were
+ * waiting for the exclusive lock are available for decoding.
+ */
+ XLogFlush(GetXLogInsertEndRecPtr());
+ end_of_wal = GetFlushRecPtr(NULL);
+
+ /*
+ * Apply the concurrent changes again. Indicate that the decoding worker
+ * won't be needed anymore.
+ */
+ process_concurrent_changes(end_of_wal, &chgcxt, true);
+
+ /* Remember info about rel before closing OldHeap */
+ relpersistence = OldHeap->rd_rel->relpersistence;
+ is_system_catalog = IsSystemRelation(OldHeap);
+
+ pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
+ PROGRESS_REPACK_PHASE_SWAP_REL_FILES);
+
+ /*
+ * Even ShareUpdateExclusiveLock should have prevented others from
+ * creating / dropping indexes (even using the CONCURRENTLY option), so we
+ * do not need to check whether the lists match.
+ */
+ forboth(lc, ind_oids_old, lc2, ind_oids_new)
+ {
+ Oid ind_old = lfirst_oid(lc);
+ Oid ind_new = lfirst_oid(lc2);
+ Oid mapped_tables[4] = {0};
+
+ swap_relation_files(ind_old, ind_new,
+ (old_table_oid == RelationRelationId),
+ false, /* swap_toast_by_content */
+ true,
+ InvalidTransactionId,
+ InvalidMultiXactId,
+ mapped_tables);
+
+#ifdef USE_ASSERT_CHECKING
+
+ /*
+ * Concurrent processing is not supported for system relations, so
+ * there should be no mapped tables.
+ */
+ for (int i = 0; i < 4; i++)
+ Assert(!OidIsValid(mapped_tables[i]));
+#endif
+ }
+
+ /* The new indexes must be visible for deletion. */
+ CommandCounterIncrement();
+
+ /* Close the old heap but keep lock until transaction commit. */
+ table_close(OldHeap, NoLock);
+ /* Close the new heap. (We didn't have to open its indexes). */
+ table_close(NewHeap, NoLock);
+
+ /* Cleanup what we don't need anymore. (And close the identity index.) */
+ release_change_context(&chgcxt);
+
+ /*
+ * Swap the relations and their TOAST relations and TOAST indexes. This
+ * also drops the new relation and its indexes.
+ *
+ * (System catalogs are currently not supported.)
+ */
+ Assert(!is_system_catalog);
+ finish_heap_swap(old_table_oid, new_table_oid,
+ is_system_catalog,
+ false, /* swap_toast_by_content */
+ false,
+ true,
+ false, /* reindex */
+ frozenXid, cutoffMulti,
+ relpersistence);
+}
+
+/*
+ * Build indexes on NewHeap according to those on OldHeap.
+ *
+ * OldIndexes is the list of index OIDs on OldHeap. The contained indexes end
+ * up locked using ShareUpdateExclusiveLock.
+ *
+ * A list of OIDs of the corresponding indexes created on NewHeap is
+ * returned. The order of items does match, so we can use these arrays to swap
+ * index storage.
+ */
+static List *
+build_new_indexes(Relation NewHeap, Relation OldHeap, List *OldIndexes)
+{
+ List *result = NIL;
+
+ pgstat_progress_update_param(PROGRESS_REPACK_PHASE,
+ PROGRESS_REPACK_PHASE_REBUILD_INDEX);
+
+ foreach_oid(oldindex, OldIndexes)
+ {
+ Oid newindex;
+ char *newName;
+ Relation ind;
+
+ ind = index_open(oldindex, ShareUpdateExclusiveLock);
+
+ newName = ChooseRelationName(get_rel_name(oldindex),
+ NULL,
+ "repacknew",
+ get_rel_namespace(ind->rd_index->indrelid),
+ false);
+ newindex = index_create_copy(NewHeap, INDEX_CREATE_SUPPRESS_PROGRESS,
+ oldindex, ind->rd_rel->reltablespace,
+ newName);
+ copy_index_constraints(ind, newindex, RelationGetRelid(NewHeap));
+ result = lappend_oid(result, newindex);
+
+ index_close(ind, NoLock);
+ }
+
+ return result;
+}
+
+/*
+ * Create a transient copy of a constraint -- supported by a transient
+ * copy of the index that supports the original constraint.
+ *
+ * When repacking a table that contains exclusion constraints, the executor
+ * relies on these constraints being properly catalogued. These copies are
+ * to support that.
+ *
+ * We don't need the constraints for anything else (the original constraints
+ * will be there once repack completes), so we add pg_depend entries so that
+ * the are dropped when the transient table is dropped.
+ */
+static void
+copy_index_constraints(Relation old_index, Oid new_index_id, Oid new_heap_id)
+{
+ ScanKeyData skey;
+ Relation rel;
+ TupleDesc desc;
+ SysScanDesc scan;
+ HeapTuple tup;
+ ObjectAddress objrel;
+
+ rel = table_open(ConstraintRelationId, RowExclusiveLock);
+ ObjectAddressSet(objrel, RelationRelationId, new_heap_id);
+
+ /*
+ * Retrieve the constraints supported by the old index and create an
+ * identical one that points to the new index.
+ */
+ ScanKeyInit(&skey,
+ Anum_pg_constraint_conrelid,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(old_index->rd_index->indrelid));
+ scan = systable_beginscan(rel, ConstraintRelidTypidNameIndexId, true,
+ NULL, 1, &skey);
+ desc = RelationGetDescr(rel);
+ while (HeapTupleIsValid(tup = systable_getnext(scan)))
+ {
+ Form_pg_constraint conform = (Form_pg_constraint) GETSTRUCT(tup);
+ Oid oid;
+ Datum values[Natts_pg_constraint] = {0};
+ bool nulls[Natts_pg_constraint] = {0};
+ bool replaces[Natts_pg_constraint] = {0};
+ HeapTuple new_tup;
+ ObjectAddress objcon;
+
+ if (conform->conindid != RelationGetRelid(old_index))
+ continue;
+
+ oid = GetNewOidWithIndex(rel, ConstraintOidIndexId,
+ Anum_pg_constraint_oid);
+ values[Anum_pg_constraint_oid - 1] = ObjectIdGetDatum(oid);
+ replaces[Anum_pg_constraint_oid - 1] = true;
+ values[Anum_pg_constraint_conrelid - 1] = ObjectIdGetDatum(new_heap_id);
+ replaces[Anum_pg_constraint_conrelid - 1] = true;
+ values[Anum_pg_constraint_conindid - 1] = ObjectIdGetDatum(new_index_id);
+ replaces[Anum_pg_constraint_conindid - 1] = true;
+
+ new_tup = heap_modify_tuple(tup, desc, values, nulls, replaces);
+
+ /* Insert it into the catalog. */
+ CatalogTupleInsert(rel, new_tup);
+
+ /* Create a dependency so it's removed when we drop the new heap. */
+ ObjectAddressSet(objcon, ConstraintRelationId, oid);
+ recordDependencyOn(&objcon, &objrel, DEPENDENCY_AUTO);
+ }
+ systable_endscan(scan);
+
+ table_close(rel, RowExclusiveLock);
+
+ CommandCounterIncrement();
+}
+
+/*
+ * Try to start a background worker to perform logical decoding of data
+ * changes applied to relation while REPACK CONCURRENTLY is copying its
+ * contents to a new table.
+ */
+static void
+start_repack_decoding_worker(Oid relid)
+{
+ Size size;
+ dsm_segment *seg;
+ DecodingWorkerShared *shared;
+ shm_mq *mq;
+ shm_mq_handle *mqh;
+ BackgroundWorker bgw;
+
+ /* Setup shared memory. */
+ size = BUFFERALIGN(offsetof(DecodingWorkerShared, error_queue)) +
+ BUFFERALIGN(REPACK_ERROR_QUEUE_SIZE);
+ seg = dsm_create(size, 0);
+ shared = (DecodingWorkerShared *) dsm_segment_address(seg);
+ shared->lsn_upto = InvalidXLogRecPtr;
+ shared->done = false;
+ SharedFileSetInit(&shared->sfs, seg);
+ shared->last_exported = -1;
+ SpinLockInit(&shared->mutex);
+ shared->dbid = MyDatabaseId;
+
+ /*
+ * This is the UserId set in cluster_rel(). Security context shouldn't be
+ * needed for decoding worker.
+ */
+ shared->roleid = GetUserId();
+ shared->relid = relid;
+ ConditionVariableInit(&shared->cv);
+ shared->backend_proc = MyProc;
+ shared->backend_pid = MyProcPid;
+ shared->backend_proc_number = MyProcNumber;
+
+ mq = shm_mq_create((char *) BUFFERALIGN(shared->error_queue),
+ REPACK_ERROR_QUEUE_SIZE);
+ shm_mq_set_receiver(mq, MyProc);
+ mqh = shm_mq_attach(mq, seg, NULL);
+
+ memset(&bgw, 0, sizeof(bgw));
+ snprintf(bgw.bgw_name, BGW_MAXLEN,
+ "REPACK decoding worker for relation \"%s\"",
+ get_rel_name(relid));
+ snprintf(bgw.bgw_type, BGW_MAXLEN, "REPACK decoding worker");
+ bgw.bgw_flags = BGWORKER_SHMEM_ACCESS |
+ BGWORKER_BACKEND_DATABASE_CONNECTION;
+ bgw.bgw_start_time = BgWorkerStart_RecoveryFinished;
+ bgw.bgw_restart_time = BGW_NEVER_RESTART;
+ snprintf(bgw.bgw_library_name, MAXPGPATH, "postgres");
+ snprintf(bgw.bgw_function_name, BGW_MAXLEN, "RepackWorkerMain");
+ bgw.bgw_main_arg = UInt32GetDatum(dsm_segment_handle(seg));
+ bgw.bgw_notify_pid = MyProcPid;
+
+ decoding_worker = palloc0_object(DecodingWorker);
+ if (!RegisterDynamicBackgroundWorker(&bgw, &decoding_worker->handle))
+ ereport(ERROR,
+ errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
+ errmsg("out of background worker slots"),
+ errhint("You might need to increase \"%s\".", "max_worker_processes"));
+
+ decoding_worker->seg = seg;
+ decoding_worker->error_mqh = mqh;
+
+ /*
+ * The decoding setup must be done before the caller can have XID assigned
+ * for any reason, otherwise the worker might end up in a deadlock,
+ * waiting for the caller's transaction to end. Therefore wait here until
+ * the worker indicates that it has the logical decoding initialized.
+ */
+ ConditionVariablePrepareToSleep(&shared->cv);
+ for (;;)
+ {
+ bool initialized;
+
+ SpinLockAcquire(&shared->mutex);
+ initialized = shared->initialized;
+ SpinLockRelease(&shared->mutex);
+
+ if (initialized)
+ break;
+
+ ConditionVariableSleep(&shared->cv, WAIT_EVENT_REPACK_WORKER_EXPORT);
+ }
+ ConditionVariableCancelSleep();
+}
+
+/*
+ * Stop the decoding worker and cleanup the related resources.
+ *
+ * The worker stops on its own when it knows there is no more work to do, but
+ * we need to stop it explicitly at least on ERROR in the launching backend.
+ */
+static void
+stop_repack_decoding_worker(void)
+{
+ BgwHandleStatus status;
+
+ /* Haven't reached the worker startup? */
+ if (decoding_worker == NULL)
+ return;
+
+ /* Could not register the worker? */
+ if (decoding_worker->handle == NULL)
+ return;
+
+ TerminateBackgroundWorker(decoding_worker->handle);
+ /* The worker should really exit before the REPACK command does. */
+ HOLD_INTERRUPTS();
+ status = WaitForBackgroundWorkerShutdown(decoding_worker->handle);
+ RESUME_INTERRUPTS();
+
+ if (status == BGWH_POSTMASTER_DIED)
+ ereport(FATAL,
+ errcode(ERRCODE_ADMIN_SHUTDOWN),
+ errmsg("postmaster exited during REPACK command"));
+
+ shm_mq_detach(decoding_worker->error_mqh);
+
+ /*
+ * If we could not cancel the current sleep due to ERROR, do that before
+ * we detach from the shared memory the condition variable is located in.
+ * If we did not, the bgworker ERROR handling code would try and fail
+ * badly.
+ */
+ ConditionVariableCancelSleep();
+
+ dsm_detach(decoding_worker->seg);
+ pfree(decoding_worker);
+ decoding_worker = NULL;
+}
+
+/*
+ * Get the initial snapshot from the decoding worker.
+ */
+static Snapshot
+get_initial_snapshot(DecodingWorker *worker)
+{
+ DecodingWorkerShared *shared;
+ char fname[MAXPGPATH];
+ BufFile *file;
+ Size snap_size;
+ char *snap_space;
+ Snapshot snapshot;
+
+ shared = (DecodingWorkerShared *) dsm_segment_address(worker->seg);
+
+ /*
+ * The worker needs to initialize the logical decoding, which usually
+ * takes some time. Therefore it makes sense to prepare for the sleep
+ * first.
+ */
+ ConditionVariablePrepareToSleep(&shared->cv);
+ for (;;)
+ {
+ int last_exported;
+
+ SpinLockAcquire(&shared->mutex);
+ last_exported = shared->last_exported;
+ SpinLockRelease(&shared->mutex);
+
+ /*
+ * Has the worker exported the file we are waiting for?
+ */
+ if (last_exported == WORKER_FILE_SNAPSHOT)
+ break;
+
+ ConditionVariableSleep(&shared->cv, WAIT_EVENT_REPACK_WORKER_EXPORT);
+ }
+ ConditionVariableCancelSleep();
+
+ /* Read the snapshot from a file. */
+ DecodingWorkerFileName(fname, shared->relid, WORKER_FILE_SNAPSHOT);
+ file = BufFileOpenFileSet(&shared->sfs.fs, fname, O_RDONLY, false);
+ BufFileReadExact(file, &snap_size, sizeof(snap_size));
+ snap_space = (char *) palloc(snap_size);
+ BufFileReadExact(file, snap_space, snap_size);
+ BufFileClose(file);
+
+ /* Restore it. */
+ snapshot = RestoreSnapshot(snap_space);
+ pfree(snap_space);
+
+ return snapshot;
+}
+
+/*
+ * Generate worker's file name into 'fname', which must be of size MAXPGPATH.
+ * If relations of the same 'relid' happen to be processed at the same time,
+ * they must be from different databases and therefore different backends must
+ * be involved.
+ */
+void
+DecodingWorkerFileName(char *fname, Oid relid, uint32 seq)
+{
+ /* The PID is already present in the fileset name, so we needn't add it */
+ snprintf(fname, MAXPGPATH, "%u-%u", relid, seq);
+}
+
+/*
+ * Handle receipt of an interrupt indicating a repack worker message.
+ *
+ * Note: this is called within a signal handler! All we can do is set
+ * a flag that will cause the next CHECK_FOR_INTERRUPTS() to invoke
+ * ProcessRepackMessages().
+ */
+void
+HandleRepackMessageInterrupt(void)
+{
+ InterruptPending = true;
+ RepackMessagePending = true;
+ SetLatch(MyLatch);
+}
+
+/*
+ * Process any queued protocol messages received from the repack worker.
+ */
+void
+ProcessRepackMessages(void)
+{
+ MemoryContext oldcontext;
+ static MemoryContext hpm_context = NULL;
+
+ /*
+ * Nothing to do if we haven't launched the worker yet or have already
+ * terminated it.
+ */
+ if (decoding_worker == NULL)
+ return;
+
+ /*
+ * This is invoked from ProcessInterrupts(), and since some of the
+ * functions it calls contain CHECK_FOR_INTERRUPTS(), there is a potential
+ * for recursive calls if more signals are received while this runs. It's
+ * unclear that recursive entry would be safe, and it doesn't seem useful
+ * even if it is safe, so let's block interrupts until done.
+ */
+ HOLD_INTERRUPTS();
+
+ /*
+ * Moreover, CurrentMemoryContext might be pointing almost anywhere. We
+ * don't want to risk leaking data into long-lived contexts, so let's do
+ * our work here in a private context that we can reset on each use.
+ */
+ if (hpm_context == NULL) /* first time through? */
+ hpm_context = AllocSetContextCreate(TopMemoryContext,
+ "ProcessRepackMessages",
+ ALLOCSET_DEFAULT_SIZES);
+ else
+ MemoryContextReset(hpm_context);
+
+ oldcontext = MemoryContextSwitchTo(hpm_context);
+
+ /* OK to process messages. Reset the flag saying there are more to do. */
+ RepackMessagePending = false;
+
+ /*
+ * Read as many messages as we can from the worker, but stop when no more
+ * messages can be read from the worker without blocking.
+ */
+ while (true)
+ {
+ shm_mq_result res;
+ Size nbytes;
+ void *data;
+
+ res = shm_mq_receive(decoding_worker->error_mqh, &nbytes,
+ &data, true);
+ if (res == SHM_MQ_WOULD_BLOCK)
+ break;
+ else if (res == SHM_MQ_SUCCESS)
+ {
+ StringInfoData msg;
+
+ initStringInfo(&msg);
+ appendBinaryStringInfo(&msg, data, nbytes);
+ ProcessRepackMessage(&msg);
+ pfree(msg.data);
+ }
+ else
+ {
+ /*
+ * The decoding worker is special in that it exits as soon as it
+ * has its work done. Thus the DETACHED result code is fine.
+ */
+ Assert(res == SHM_MQ_DETACHED);
+
+ break;
+ }
+ }
+
+ MemoryContextSwitchTo(oldcontext);
+
+ /* Might as well clear the context on our way out */
+ MemoryContextReset(hpm_context);
+
+ RESUME_INTERRUPTS();
+}
+
+/*
+ * Process a single protocol message received from a single parallel worker.
+ */
+static void
+ProcessRepackMessage(StringInfo msg)
+{
+ char msgtype;
+
+ msgtype = pq_getmsgbyte(msg);
+
+ switch (msgtype)
+ {
+ case PqMsg_ErrorResponse:
+ case PqMsg_NoticeResponse:
+ {
+ ErrorData edata;
+
+ /* Parse ErrorResponse or NoticeResponse. */
+ pq_parse_errornotice(msg, &edata);
+
+ /* Death of a worker isn't enough justification for suicide. */
+ edata.elevel = Min(edata.elevel, ERROR);
+
+ /*
+ * Add a context line to show that this is a message
+ * propagated from the worker. Otherwise, it can sometimes be
+ * confusing to understand what actually happened.
+ */
+ if (edata.context)
+ edata.context = psprintf("%s\n%s", edata.context,
+ _("REPACK decoding worker"));
+ else
+ edata.context = pstrdup(_("REPACK decoding worker"));
+
+ /* Rethrow error or print notice. */
+ ThrowErrorData(&edata);
+
+ break;
+ }
+
+ default:
+ {
+ elog(ERROR, "unrecognized message type received from decoding worker: %c (message length %d bytes)",
+ msgtype, msg->len);
+ }
+ }
+}
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * repack_worker.c
+ * Implementation of the background worker for ad-hoc logical decoding
+ * during REPACK (CONCURRENTLY).
+ *
+ *
+ * Copyright (c) 2026, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/commands/repack_worker.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/table.h"
+#include "access/xlog_internal.h"
+#include "access/xlogutils.h"
+#include "access/xlogwait.h"
+#include "commands/repack.h"
+#include "commands/repack_internal.h"
+#include "libpq/pqmq.h"
+#include "replication/snapbuild.h"
+#include "storage/ipc.h"
+#include "storage/proc.h"
+#include "tcop/tcopprot.h"
+#include "utils/memutils.h"
+
+#define REPL_PLUGIN_NAME "pgrepack"
+
+static void RepackWorkerShutdown(int code, Datum arg);
+static LogicalDecodingContext *repack_setup_logical_decoding(Oid relid);
+static void repack_cleanup_logical_decoding(LogicalDecodingContext *ctx);
+static void export_initial_snapshot(Snapshot snapshot,
+ DecodingWorkerShared *shared);
+static bool decode_concurrent_changes(LogicalDecodingContext *ctx,
+ DecodingWorkerShared *shared);
+
+/* Is this process a REPACK worker? */
+static bool am_repack_worker = false;
+
+/* The WAL segment being decoded. */
+static XLogSegNo repack_current_segment = 0;
+
+/*
+ * Keep track of the table we're processing, to skip logical decoding of data
+ * from other relations.
+ */
+static RelFileLocator repacked_rel_locator = {.relNumber = InvalidOid};
+static RelFileLocator repacked_rel_toast_locator = {.relNumber = InvalidOid};
+
+
+/* REPACK decoding worker entry point */
+void
+RepackWorkerMain(Datum main_arg)
+{
+ dsm_segment *seg;
+ DecodingWorkerShared *shared;
+ shm_mq *mq;
+ shm_mq_handle *mqh;
+ LogicalDecodingContext *decoding_ctx;
+ SharedFileSet *sfs;
+ Snapshot snapshot;
+
+ am_repack_worker = true;
+
+ /*
+ * Override the default bgworker_die() with die() so we can use
+ * CHECK_FOR_INTERRUPTS().
+ */
+ pqsignal(SIGTERM, die);
+ BackgroundWorkerUnblockSignals();
+
+ seg = dsm_attach(DatumGetUInt32(main_arg));
+ if (seg == NULL)
+ ereport(ERROR,
+ errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+ errmsg("could not map dynamic shared memory segment"));
+
+ shared = (DecodingWorkerShared *) dsm_segment_address(seg);
+ shared->dsm_seg = seg;
+
+ /* Arrange to signal the leader if we exit. */
+ before_shmem_exit(RepackWorkerShutdown, PointerGetDatum(shared));
+
+ /*
+ * Join locking group - see the comments around the call of
+ * start_repack_decoding_worker().
+ */
+ if (!BecomeLockGroupMember(shared->backend_proc, shared->backend_pid))
+ return; /* The leader is not running anymore. */
+
+ /*
+ * Setup a queue to send error messages to the backend that launched this
+ * worker.
+ */
+ mq = (shm_mq *) (char *) BUFFERALIGN(shared->error_queue);
+ shm_mq_set_sender(mq, MyProc);
+ mqh = shm_mq_attach(mq, seg, NULL);
+ pq_redirect_to_shm_mq(seg, mqh);
+ pq_set_parallel_leader(shared->backend_pid,
+ shared->backend_proc_number);
+
+ /* Connect to the database. */
+ BackgroundWorkerInitializeConnectionByOid(shared->dbid, shared->roleid, 0);
+
+ /*
+ * Transaction is needed to open relation, and it also provides us with a
+ * resource owner.
+ */
+ StartTransactionCommand();
+
+ shared = (DecodingWorkerShared *) dsm_segment_address(seg);
+
+ /*
+ * Not sure the spinlock is needed here - the backend should not change
+ * anything in the shared memory until we have serialized the snapshot.
+ */
+ SpinLockAcquire(&shared->mutex);
+ Assert(!XLogRecPtrIsValid(shared->lsn_upto));
+ sfs = &shared->sfs;
+ SpinLockRelease(&shared->mutex);
+
+ SharedFileSetAttach(sfs, seg);
+
+ /*
+ * Prepare to capture the concurrent data changes ourselves.
+ */
+ decoding_ctx = repack_setup_logical_decoding(shared->relid);
+
+ /* Announce that we're ready. */
+ SpinLockAcquire(&shared->mutex);
+ shared->initialized = true;
+ SpinLockRelease(&shared->mutex);
+ ConditionVariableSignal(&shared->cv);
+
+ /* There doesn't seem to a nice API to set these */
+ XactIsoLevel = XACT_REPEATABLE_READ;
+ XactReadOnly = true;
+
+ /* Build the initial snapshot and export it. */
+ snapshot = SnapBuildInitialSnapshot(decoding_ctx->snapshot_builder);
+ export_initial_snapshot(snapshot, shared);
+
+ /*
+ * Only historic snapshots should be used now. Do not let us restrict the
+ * progress of xmin horizon.
+ */
+ InvalidateCatalogSnapshot();
+
+ for (;;)
+ {
+ bool stop = decode_concurrent_changes(decoding_ctx, shared);
+
+ if (stop)
+ break;
+
+ }
+
+ /* Cleanup. */
+ repack_cleanup_logical_decoding(decoding_ctx);
+ CommitTransactionCommand();
+}
+
+/*
+ * See ParallelWorkerShutdown for details.
+ */
+static void
+RepackWorkerShutdown(int code, Datum arg)
+{
+ DecodingWorkerShared *shared = (DecodingWorkerShared *) DatumGetPointer(arg);
+
+ SendProcSignal(shared->backend_pid,
+ PROCSIG_REPACK_MESSAGE,
+ shared->backend_proc_number);
+
+ dsm_detach(shared->dsm_seg);
+}
+
+bool
+AmRepackWorker(void)
+{
+ return am_repack_worker;
+}
+
+/*
+ * This function is much like pg_create_logical_replication_slot() except that
+ * the new slot is neither released (if anyone else could read changes from
+ * our slot, we could miss changes other backends do while we copy the
+ * existing data into temporary table), nor persisted (it's easier to handle
+ * crash by restarting all the work from scratch).
+ */
+static LogicalDecodingContext *
+repack_setup_logical_decoding(Oid relid)
+{
+ Relation rel;
+ Oid toastrelid;
+ LogicalDecodingContext *ctx;
+ NameData slotname;
+ RepackDecodingState *dstate;
+ MemoryContext oldcxt;
+
+ /*
+ * REPACK CONCURRENTLY is not allowed in a transaction block, so this
+ * should never fire.
+ */
+ Assert(!TransactionIdIsValid(GetTopTransactionIdIfAny()));
+
+ /*
+ * Make sure we can use logical decoding.
+ */
+ CheckSlotPermissions();
+ CheckLogicalDecodingRequirements();
+
+ /*
+ * A single backend should not execute multiple REPACK commands at a time,
+ * so use PID to make the slot unique.
+ *
+ * RS_TEMPORARY so that the slot gets cleaned up on ERROR.
+ */
+ snprintf(NameStr(slotname), NAMEDATALEN, "repack_%d", MyProcPid);
+ ReplicationSlotCreate(NameStr(slotname), true, RS_TEMPORARY, false, false,
+ false);
+
+ EnsureLogicalDecodingEnabled();
+
+ /*
+ * Neither prepare_write nor do_write callback nor update_progress is
+ * useful for us.
+ */
+ ctx = CreateInitDecodingContext(REPL_PLUGIN_NAME,
+ NIL,
+ true,
+ InvalidXLogRecPtr,
+ XL_ROUTINE(.page_read = read_local_xlog_page,
+ .segment_open = wal_segment_open,
+ .segment_close = wal_segment_close),
+ NULL, NULL, NULL);
+
+ /*
+ * We don't have control on setting fast_forward, so at least check it.
+ */
+ Assert(!ctx->fast_forward);
+
+ /* Avoid logical decoding of other relations. */
+ rel = table_open(relid, AccessShareLock);
+ repacked_rel_locator = rel->rd_locator;
+ toastrelid = rel->rd_rel->reltoastrelid;
+ if (OidIsValid(toastrelid))
+ {
+ Relation toastrel;
+
+ /* Avoid logical decoding of other TOAST relations. */
+ toastrel = table_open(toastrelid, AccessShareLock);
+ repacked_rel_toast_locator = toastrel->rd_locator;
+ table_close(toastrel, AccessShareLock);
+ }
+ table_close(rel, AccessShareLock);
+
+ DecodingContextFindStartpoint(ctx);
+
+ /*
+ * decode_concurrent_changes() needs non-blocking callback.
+ */
+ ctx->reader->routine.page_read = read_local_xlog_page_no_wait;
+
+ /* Some WAL records should have been read. */
+ Assert(ctx->reader->EndRecPtr != InvalidXLogRecPtr);
+
+ /*
+ * Initialize repack_current_segment so that we can notice WAL segment
+ * boundaries.
+ */
+ XLByteToSeg(ctx->reader->EndRecPtr, repack_current_segment,
+ wal_segment_size);
+
+ /* Our private state belongs to the decoding context. */
+ oldcxt = MemoryContextSwitchTo(ctx->context);
+
+ /*
+ * read_local_xlog_page_no_wait() needs to be able to indicate the end of
+ * WAL.
+ */
+ ctx->reader->private_data = palloc0_object(ReadLocalXLogPageNoWaitPrivate);
+ dstate = palloc0_object(RepackDecodingState);
+ MemoryContextSwitchTo(oldcxt);
+
+#ifdef USE_ASSERT_CHECKING
+ dstate->relid = relid;
+#endif
+
+ dstate->change_cxt = AllocSetContextCreate(ctx->context,
+ "REPACK - change",
+ ALLOCSET_DEFAULT_SIZES);
+
+ /* The file will be set as soon as we have it opened. */
+ dstate->file = NULL;
+
+ /*
+ * Memory context and resource owner for long-lived resources.
+ */
+ dstate->worker_cxt = CurrentMemoryContext;
+ dstate->worker_resowner = CurrentResourceOwner;
+
+ ctx->output_writer_private = dstate;
+
+ return ctx;
+}
+
+static void
+repack_cleanup_logical_decoding(LogicalDecodingContext *ctx)
+{
+ RepackDecodingState *dstate;
+
+ dstate = (RepackDecodingState *) ctx->output_writer_private;
+ if (dstate->slot)
+ ExecDropSingleTupleTableSlot(dstate->slot);
+
+ FreeDecodingContext(ctx);
+ ReplicationSlotDropAcquired();
+}
+
+/*
+ * Make snapshot available to the backend that launched the decoding worker.
+ */
+static void
+export_initial_snapshot(Snapshot snapshot, DecodingWorkerShared *shared)
+{
+ char fname[MAXPGPATH];
+ BufFile *file;
+ Size snap_size;
+ char *snap_space;
+
+ snap_size = EstimateSnapshotSpace(snapshot);
+ snap_space = (char *) palloc(snap_size);
+ SerializeSnapshot(snapshot, snap_space);
+
+ DecodingWorkerFileName(fname, shared->relid, shared->last_exported + 1);
+ file = BufFileCreateFileSet(&shared->sfs.fs, fname);
+ /* To make restoration easier, write the snapshot size first. */
+ BufFileWrite(file, &snap_size, sizeof(snap_size));
+ BufFileWrite(file, snap_space, snap_size);
+ pfree(snap_space);
+ BufFileClose(file);
+
+ /* Increase the counter to tell the backend that the file is available. */
+ SpinLockAcquire(&shared->mutex);
+ shared->last_exported++;
+ SpinLockRelease(&shared->mutex);
+ ConditionVariableSignal(&shared->cv);
+}
+
+/*
+ * Decode logical changes from the WAL sequence and store them to a file.
+ *
+ * If true is returned, there is no more work for the worker.
+ */
+static bool
+decode_concurrent_changes(LogicalDecodingContext *ctx,
+ DecodingWorkerShared *shared)
+{
+ RepackDecodingState *dstate;
+ XLogRecPtr lsn_upto;
+ bool done;
+ char fname[MAXPGPATH];
+
+ dstate = (RepackDecodingState *) ctx->output_writer_private;
+
+ /* Open the output file. */
+ DecodingWorkerFileName(fname, shared->relid, shared->last_exported + 1);
+ dstate->file = BufFileCreateFileSet(&shared->sfs.fs, fname);
+
+ SpinLockAcquire(&shared->mutex);
+ lsn_upto = shared->lsn_upto;
+ done = shared->done;
+ SpinLockRelease(&shared->mutex);
+
+ while (true)
+ {
+ XLogRecord *record;
+ XLogSegNo segno_new;
+ char *errm = NULL;
+ XLogRecPtr end_lsn;
+
+ CHECK_FOR_INTERRUPTS();
+
+ record = XLogReadRecord(ctx->reader, &errm);
+ if (record)
+ {
+ LogicalDecodingProcessRecord(ctx, ctx->reader);
+
+ /*
+ * If WAL segment boundary has been crossed, inform the decoding
+ * system that the catalog_xmin can advance.
+ */
+ end_lsn = ctx->reader->EndRecPtr;
+ XLByteToSeg(end_lsn, segno_new, wal_segment_size);
+ if (segno_new != repack_current_segment)
+ {
+ LogicalConfirmReceivedLocation(end_lsn);
+ elog(DEBUG1, "REPACK: confirmed receive location %X/%X",
+ (uint32) (end_lsn >> 32), (uint32) end_lsn);
+ repack_current_segment = segno_new;
+ }
+ }
+ else
+ {
+ ReadLocalXLogPageNoWaitPrivate *priv;
+
+ if (errm)
+ ereport(ERROR,
+ errmsg("%s", errm));
+
+ /*
+ * In the decoding loop we do not want to get blocked when there
+ * is no more WAL available, otherwise the loop would become
+ * uninterruptible.
+ */
+ priv = (ReadLocalXLogPageNoWaitPrivate *) ctx->reader->private_data;
+ if (priv->end_of_wal)
+ /* Do not miss the end of WAL condition next time. */
+ priv->end_of_wal = false;
+ else
+ ereport(ERROR,
+ errmsg("could not read WAL record"));
+ }
+
+ /*
+ * Whether we could read new record or not, keep checking if
+ * 'lsn_upto' was specified.
+ */
+ if (!XLogRecPtrIsValid(lsn_upto))
+ {
+ SpinLockAcquire(&shared->mutex);
+ lsn_upto = shared->lsn_upto;
+ /* 'done' should be set at the same time as 'lsn_upto' */
+ done = shared->done;
+ SpinLockRelease(&shared->mutex);
+ }
+ if (XLogRecPtrIsValid(lsn_upto) &&
+ ctx->reader->EndRecPtr >= lsn_upto)
+ break;
+
+ if (record == NULL)
+ {
+ int64 timeout = 0;
+ WaitLSNResult res;
+
+ /*
+ * Before we retry reading, wait until new WAL is flushed.
+ *
+ * There is a race condition such that the backend executing
+ * REPACK determines 'lsn_upto', but before it sets the shared
+ * variable, we reach the end of WAL. In that case we'd need to
+ * wait until the next WAL flush (unrelated to REPACK). Although
+ * that should not be a problem in a busy system, it might be
+ * noticeable in other cases, including regression tests (which
+ * are not necessarily executed in parallel). Therefore it makes
+ * sense to use timeout.
+ *
+ * If lsn_upto is valid, WAL records having LSN lower than that
+ * should already have been flushed to disk.
+ */
+ if (!XLogRecPtrIsValid(lsn_upto))
+ timeout = 100L;
+ res = WaitForLSN(WAIT_LSN_TYPE_PRIMARY_FLUSH,
+ ctx->reader->EndRecPtr + 1,
+ timeout);
+ if (res != WAIT_LSN_RESULT_SUCCESS &&
+ res != WAIT_LSN_RESULT_TIMEOUT)
+ ereport(ERROR,
+ errmsg("waiting for WAL failed"));
+ }
+ }
+
+ /*
+ * Close the file so we can make it available to the backend.
+ */
+ BufFileClose(dstate->file);
+ dstate->file = NULL;
+ SpinLockAcquire(&shared->mutex);
+ shared->lsn_upto = InvalidXLogRecPtr;
+ shared->last_exported++;
+ SpinLockRelease(&shared->mutex);
+ ConditionVariableSignal(&shared->cv);
+
+ return done;
+}
+
+/*
+ * Does the WAL record contain a data change that this backend does not need
+ * to decode on behalf of REPACK (CONCURRENTLY)?
+ */
+bool
+change_useless_for_repack(XLogRecordBuffer *buf)
+{
+ XLogReaderState *r = buf->record;
+ RelFileLocator locator;
+
+ /* TOAST locator should not be set unless the main is. */
+ Assert(!OidIsValid(repacked_rel_toast_locator.relNumber) ||
+ OidIsValid(repacked_rel_locator.relNumber));
+
+ /*
+ * Backends not involved in REPACK (CONCURRENTLY) should not do the
+ * filtering.
+ */
+ if (!OidIsValid(repacked_rel_locator.relNumber))
+ return false;
+
+ /*
+ * If the record does not contain the block 0, it's probably not INSERT /
+ * UPDATE / DELETE. In any case, we do not have enough information to
+ * filter the change out.
+ */
+ if (!XLogRecGetBlockTagExtended(r, 0, &locator, NULL, NULL, NULL))
+ return false;
+
+ /*
+ * Decode the change if it belongs to the table we are repacking, or if it
+ * belongs to its TOAST relation.
+ */
+ if (RelFileLocatorEquals(locator, repacked_rel_locator))
+ return false;
+ if (OidIsValid(repacked_rel_toast_locator.relNumber) &&
+ RelFileLocatorEquals(locator, repacked_rel_toast_locator))
+ return false;
+
+ /* Filter out changes of other tables. */
+ return true;
+}
finish_heap_swap(tab->relid, OIDNewHeap,
false, false, true,
!OidIsValid(tab->newTableSpace),
+ true, /* reindex */
RecentXmin,
ReadNextMultiXactId(),
persistence);
TransactionId lastSaneFrozenXid,
MultiXactId lastSaneMinMulti);
static bool vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
- BufferAccessStrategy bstrategy);
+ BufferAccessStrategy bstrategy, bool isTopLevel);
static double compute_parallel_delay(void);
static VacOptValue get_vacoptval_from_boolean(DefElem *def);
static bool vac_tid_reaped(ItemPointer itemptr, void *state);
if (params->options & VACOPT_VACUUM)
{
- if (!vacuum_rel(vrel->oid, vrel->relation, *params, bstrategy))
+ if (!vacuum_rel(vrel->oid, vrel->relation, *params, bstrategy,
+ isTopLevel))
continue;
}
*/
static bool
vacuum_rel(Oid relid, RangeVar *relation, VacuumParams params,
- BufferAccessStrategy bstrategy)
+ BufferAccessStrategy bstrategy, bool isTopLevel)
{
LOCKMODE lmode;
Relation rel;
/* VACUUM FULL is a variant of REPACK; see repack.c */
cluster_rel(REPACK_COMMAND_VACUUMFULL, rel, InvalidOid,
- &cluster_params);
+ &cluster_params, isTopLevel);
/* cluster_rel closes the relation, but keeps lock */
rel = NULL;
toast_vacuum_params.options |= VACOPT_PROCESS_MAIN;
toast_vacuum_params.toast_parent = relid;
- vacuum_rel(toast_relid, NULL, toast_vacuum_params, bstrategy);
+ vacuum_rel(toast_relid, NULL, toast_vacuum_params, bstrategy,
+ isTopLevel);
}
/*
#include "postgres.h"
#include "access/parallel.h"
+#include "commands/repack.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
#include "libpq/pqmq.h"
SendProcSignal(pq_mq_parallel_leader_pid,
PROCSIG_PARALLEL_APPLY_MESSAGE,
pq_mq_parallel_leader_proc_number);
+ else if (AmRepackWorker())
+ SendProcSignal(pq_mq_parallel_leader_pid,
+ PROCSIG_REPACK_MESSAGE,
+ pq_mq_parallel_leader_proc_number);
else
{
Assert(IsParallelWorker());
subdir('jit/llvm')
subdir('replication/libpqwalreceiver')
subdir('replication/pgoutput')
+subdir('replication/pgrepack')
subdir('snowball')
subdir('utils/mb/conversion_procs')
#include "postgres.h"
#include "access/parallel.h"
+#include "commands/repack.h"
#include "libpq/pqsignal.h"
#include "miscadmin.h"
#include "pgstat.h"
.fn_name = "ParallelWorkerMain",
.fn_addr = ParallelWorkerMain
},
+ {
+ .fn_name = "RepackWorkerMain",
+ .fn_addr = RepackWorkerMain
+ },
{
.fn_name = "SequenceSyncWorkerMain",
.fn_addr = SequenceSyncWorkerMain
#include "access/xlogreader.h"
#include "access/xlogrecord.h"
#include "catalog/pg_control.h"
+#include "commands/repack.h"
#include "replication/decode.h"
#include "replication/logical.h"
#include "replication/message.h"
{
case XLOG_HEAP2_MULTI_INSERT:
if (SnapBuildProcessChange(builder, xid, buf->origptr) &&
- !ctx->fast_forward)
+ !ctx->fast_forward &&
+ !change_useless_for_repack(buf))
DecodeMultiInsert(ctx, buf);
break;
case XLOG_HEAP2_NEW_CID:
{
case XLOG_HEAP_INSERT:
if (SnapBuildProcessChange(builder, xid, buf->origptr) &&
- !ctx->fast_forward)
+ !ctx->fast_forward &&
+ !change_useless_for_repack(buf))
DecodeInsert(ctx, buf);
break;
case XLOG_HEAP_HOT_UPDATE:
case XLOG_HEAP_UPDATE:
if (SnapBuildProcessChange(builder, xid, buf->origptr) &&
- !ctx->fast_forward)
+ !ctx->fast_forward &&
+ !change_useless_for_repack(buf))
DecodeUpdate(ctx, buf);
break;
case XLOG_HEAP_DELETE:
if (SnapBuildProcessChange(builder, xid, buf->origptr) &&
- !ctx->fast_forward)
+ !ctx->fast_forward &&
+ !change_useless_for_repack(buf))
DecodeDelete(ctx, buf);
break;
case XLOG_HEAP_TRUNCATE:
if (SnapBuildProcessChange(builder, xid, buf->origptr) &&
- !ctx->fast_forward)
+ !ctx->fast_forward &&
+ !change_useless_for_repack(buf))
DecodeTruncate(ctx, buf);
break;
case XLOG_HEAP_CONFIRM:
if (SnapBuildProcessChange(builder, xid, buf->origptr) &&
- !ctx->fast_forward)
+ !ctx->fast_forward &&
+ !change_useless_for_repack(buf))
DecodeSpecConfirm(ctx, buf);
break;
xlrec = (xl_heap_delete *) XLogRecGetData(r);
+ /*
+ * Skip changes that were marked as ignorable at origin.
+ *
+ * (This is used for changes that affect relations not visible to other
+ * transactions, such as the transient table during concurrent repack.)
+ */
+ if (xlrec->flags & XLH_DELETE_NO_LOGICAL)
+ return;
+
/* only interested in our database */
XLogRecGetBlockTag(r, 0, &target_locator, NULL, NULL);
if (target_locator.dbOid != ctx->slot->data.database)
--- /dev/null
+#-------------------------------------------------------------------------
+#
+# Makefile--
+# Makefile for src/backend/replication/pgrepack
+#
+# IDENTIFICATION
+# src/backend/replication/pgrepack
+#
+#-------------------------------------------------------------------------
+
+subdir = src/backend/replication/pgrepack
+top_builddir = ../../../..
+include $(top_builddir)/src/Makefile.global
+
+OBJS = \
+ $(WIN32RES) \
+ pgrepack.o
+PGFILEDESC = "pgrepack - logical replication output plugin for REPACK"
+NAME = pgrepack
+
+all: all-shared-lib
+
+include $(top_srcdir)/src/Makefile.shlib
+
+install: all installdirs install-lib
+
+installdirs: installdirs-lib
+
+uninstall: uninstall-lib
+
+clean distclean: clean-lib
+ rm -f $(OBJS)
--- /dev/null
+# Copyright (c) 2026, PostgreSQL Global Development Group
+
+pgrepack_sources = files(
+ 'pgrepack.c',
+)
+
+if host_system == 'windows'
+ pgrepack_sources += rc_lib_gen.process(win32ver_rc, extra_args: [
+ '--NAME', 'pgrepack',
+ '--FILEDESC', 'pgrepack - logical replication output plugin for REPACK',])
+endif
+
+pgrepack = shared_module('pgrepack',
+ pgrepack_sources,
+ kwargs: pg_mod_args,
+)
+
+backend_targets += pgrepack
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * pgrepack.c
+ * Logical Replication output plugin for REPACK command
+ *
+ * Copyright (c) 2026, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/backend/replication/pgrepack/pgrepack.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/detoast.h"
+#include "commands/repack_internal.h"
+#include "replication/snapbuild.h"
+#include "utils/memutils.h"
+
+PG_MODULE_MAGIC;
+
+static void repack_startup(LogicalDecodingContext *ctx,
+ OutputPluginOptions *opt, bool is_init);
+static void repack_shutdown(LogicalDecodingContext *ctx);
+static void repack_begin_txn(LogicalDecodingContext *ctx,
+ ReorderBufferTXN *txn);
+static void repack_commit_txn(LogicalDecodingContext *ctx,
+ ReorderBufferTXN *txn, XLogRecPtr commit_lsn);
+static void repack_process_change(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
+ Relation rel, ReorderBufferChange *change);
+static void repack_store_change(LogicalDecodingContext *ctx, Relation relation,
+ ConcurrentChangeKind kind, HeapTuple tuple);
+
+void
+_PG_output_plugin_init(OutputPluginCallbacks *cb)
+{
+ cb->startup_cb = repack_startup;
+ cb->begin_cb = repack_begin_txn;
+ cb->change_cb = repack_process_change;
+ cb->commit_cb = repack_commit_txn;
+ cb->shutdown_cb = repack_shutdown;
+}
+
+
+/* initialize this plugin */
+static void
+repack_startup(LogicalDecodingContext *ctx, OutputPluginOptions *opt,
+ bool is_init)
+{
+ ctx->output_plugin_private = NULL;
+
+ /* Probably unnecessary, as we don't use the SQL interface ... */
+ opt->output_type = OUTPUT_PLUGIN_BINARY_OUTPUT;
+
+ if (ctx->output_plugin_options != NIL)
+ {
+ ereport(ERROR,
+ errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("this plugin does not expect any options"));
+ }
+}
+
+static void
+repack_shutdown(LogicalDecodingContext *ctx)
+{
+}
+
+/*
+ * As we don't release the slot during processing of particular table, there's
+ * no room for SQL interface, even for debugging purposes. Therefore we need
+ * neither OutputPluginPrepareWrite() nor OutputPluginWrite() in the plugin
+ * callbacks. (Although we might want to write custom callbacks, this API
+ * seems to be unnecessarily generic for our purposes.)
+ */
+
+/* BEGIN callback */
+static void
+repack_begin_txn(LogicalDecodingContext *ctx, ReorderBufferTXN *txn)
+{
+}
+
+/* COMMIT callback */
+static void
+repack_commit_txn(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
+ XLogRecPtr commit_lsn)
+{
+}
+
+/*
+ * Callback for individual changed tuples
+ */
+static void
+repack_process_change(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
+ Relation relation, ReorderBufferChange *change)
+{
+ RepackDecodingState *private PG_USED_FOR_ASSERTS_ONLY =
+ (RepackDecodingState *) ctx->output_writer_private;
+
+ /* Changes of other relation should not have been decoded. */
+ Assert(RelationGetRelid(relation) == private->relid);
+
+ /* Decode entry depending on its type */
+ switch (change->action)
+ {
+ case REORDER_BUFFER_CHANGE_INSERT:
+ {
+ HeapTuple newtuple;
+
+ newtuple = change->data.tp.newtuple;
+
+ /*
+ * Identity checks in the main function should have made this
+ * impossible.
+ */
+ if (newtuple == NULL)
+ elog(ERROR, "incomplete insert info");
+
+ repack_store_change(ctx, relation, CHANGE_INSERT, newtuple);
+ }
+ break;
+ case REORDER_BUFFER_CHANGE_UPDATE:
+ {
+ HeapTuple oldtuple,
+ newtuple;
+
+ oldtuple = change->data.tp.oldtuple;
+ newtuple = change->data.tp.newtuple;
+
+ if (newtuple == NULL)
+ elog(ERROR, "incomplete update info");
+
+ if (oldtuple != NULL)
+ repack_store_change(ctx, relation, CHANGE_UPDATE_OLD, oldtuple);
+
+ repack_store_change(ctx, relation, CHANGE_UPDATE_NEW, newtuple);
+ }
+ break;
+ case REORDER_BUFFER_CHANGE_DELETE:
+ {
+ HeapTuple oldtuple;
+
+ oldtuple = change->data.tp.oldtuple;
+
+ if (oldtuple == NULL)
+ elog(ERROR, "incomplete delete info");
+
+ repack_store_change(ctx, relation, CHANGE_DELETE, oldtuple);
+ }
+ break;
+ default:
+
+ /*
+ * Should not come here. This includes TRUNCATE of the table being
+ * processed. heap_decode() cannot check the file locator easily,
+ * but we assume that TRUNCATE uses AccessExclusiveLock on the
+ * table so it should not occur during REPACK (CONCURRENTLY).
+ */
+ Assert(false);
+ break;
+ }
+}
+
+/*
+ * Write the given tuple, with the given change kind, to the repack spill
+ * file. Later, the repack decoding worker can read these and replay
+ * the operations on the new copy of the table.
+ *
+ * For each change affecting the table being repacked, we store enough
+ * information about each tuple in it, so that it can be replayed in the
+ * new copy of the table.
+ */
+static void
+repack_store_change(LogicalDecodingContext *ctx, Relation relation,
+ ConcurrentChangeKind kind, HeapTuple tuple)
+{
+ RepackDecodingState *dstate;
+ MemoryContext oldcxt;
+ BufFile *file;
+ List *attrs_ext = NIL;
+ int natt_ext;
+
+ dstate = (RepackDecodingState *) ctx->output_writer_private;
+ file = dstate->file;
+
+ /* Store the change kind. */
+ BufFileWrite(file, &kind, 1);
+
+ /* Use a frequently-reset context to avoid dealing with leaks manually */
+ oldcxt = MemoryContextSwitchTo(dstate->change_cxt);
+
+ /*
+ * If the tuple contains "external indirect" attributes, we need to write
+ * the contents to the file because we have no control over that memory.
+ */
+ if (HeapTupleHasExternal(tuple))
+ {
+ TupleDesc desc = RelationGetDescr(relation);
+ TupleTableSlot *slot;
+
+ /* Initialize the slot, if not done already */
+ if (dstate->slot == NULL)
+ {
+ ResourceOwner saveResourceOwner;
+
+ MemoryContextSwitchTo(dstate->worker_cxt);
+ saveResourceOwner = CurrentResourceOwner;
+ CurrentResourceOwner = dstate->worker_resowner;
+ dstate->slot = MakeSingleTupleTableSlot(desc, &TTSOpsHeapTuple);
+ MemoryContextSwitchTo(dstate->change_cxt);
+ CurrentResourceOwner = saveResourceOwner;
+ }
+
+ slot = dstate->slot;
+ ExecStoreHeapTuple(tuple, slot, false);
+
+ /*
+ * Loop over all attributes, and find out which ones we need to spill
+ * separately, to wit: each one that's a non-null varlena and stored
+ * out of line.
+ */
+ for (int i = 0; i < desc->natts; i++)
+ {
+ CompactAttribute *attr = TupleDescCompactAttr(desc, i);
+ varlena *varlen;
+
+ if (attr->attisdropped || attr->attlen != -1 ||
+ slot_attisnull(slot, i + 1))
+ continue;
+
+ slot_getsomeattrs(slot, i + 1);
+
+ /*
+ * This is a non-null varlena datum, but we only care if it's
+ * out-of-line
+ */
+ varlen = (varlena *) DatumGetPointer(slot->tts_values[i]);
+ if (!VARATT_IS_EXTERNAL(varlen))
+ continue;
+
+ /*
+ * We spill any indirect-external attributes separately from the
+ * heap tuple. Anything else is written as is.
+ */
+ if (VARATT_IS_EXTERNAL_INDIRECT(varlen))
+ attrs_ext = lappend(attrs_ext, varlen);
+ else
+ {
+ /*
+ * Logical decoding should not produce "external expanded"
+ * attributes (those actually should never appear on disk), so
+ * only TOASTed attribute can be seen here.
+ *
+ * We get here if the table has external values but only
+ * in-line values are being updated now.
+ */
+ Assert(VARATT_IS_EXTERNAL_ONDISK(varlen));
+ }
+ }
+
+ ExecClearTuple(slot);
+ }
+
+ /*
+ * First, write the original heap tuple, prefixed by its length. Note
+ * that the external-toast tag for each toasted attribute will be present
+ * in what we write, so that we know where to restore each one later.
+ */
+ BufFileWrite(file, &tuple->t_len, sizeof(tuple->t_len));
+ BufFileWrite(file, tuple->t_data, tuple->t_len);
+
+ /* Then, write the number of external attributes we found. */
+ natt_ext = list_length(attrs_ext);
+ BufFileWrite(file, &natt_ext, sizeof(natt_ext));
+
+ /* Finally, the attributes themselves, if any */
+ foreach_ptr(varlena, attr_val, attrs_ext)
+ {
+ attr_val = detoast_external_attr(attr_val);
+ BufFileWrite(file, attr_val, VARSIZE_ANY(attr_val));
+ /* These attributes could be large, so free them right away */
+ pfree(attr_val);
+ }
+
+ /* Cleanup. */
+ MemoryContextSwitchTo(oldcxt);
+ MemoryContextReset(dstate->change_cxt);
+}
if (CheckProcSignal(PROCSIG_PARALLEL_APPLY_MESSAGE))
HandleParallelApplyMessageInterrupt();
+ if (CheckProcSignal(PROCSIG_REPACK_MESSAGE))
+ HandleRepackMessageInterrupt();
+
if (CheckProcSignal(PROCSIG_RECOVERY_CONFLICT))
HandleRecoveryConflictInterrupt();
if (ParallelApplyMessagePending)
ProcessParallelApplyMessages();
+
+ if (RepackMessagePending)
+ ProcessRepackMessages();
}
/*
RECOVERY_CONFLICT_TABLESPACE "Waiting for recovery conflict resolution for dropping a tablespace."
RECOVERY_END_COMMAND "Waiting for <xref linkend="guc-recovery-end-command"/> to complete."
RECOVERY_PAUSE "Waiting for recovery to be resumed."
+REPACK_WORKER_EXPORT "Waiting for decoding worker to export a new output file."
REPLICATION_ORIGIN_DROP "Waiting for a replication origin to become inactive so it can be dropped."
REPLICATION_SLOT_DROP "Waiting for a replication slot to become inactive so it can be dropped."
RESTORE_COMMAND "Waiting for <xref linkend="guc-restore-command"/> to complete."
* one word, so the above test is correct.
*/
if (ends_with(prev_wd, '(') || ends_with(prev_wd, ','))
- COMPLETE_WITH("ANALYZE", "VERBOSE");
- else if (TailMatches("ANALYZE", "VERBOSE"))
+ COMPLETE_WITH("ANALYZE", "CONCURRENTLY", "VERBOSE");
+ else if (TailMatches("ANALYZE", "CONCURRENTLY", "VERBOSE"))
COMPLETE_WITH("ON", "OFF");
}
#define XLH_DELETE_CONTAINS_OLD_KEY (1<<2)
#define XLH_DELETE_IS_SUPER (1<<3)
#define XLH_DELETE_IS_PARTITION_MOVE (1<<4)
+/* See heap_delete() */
+#define XLH_DELETE_NO_LOGICAL (1<<5)
/* convenience macro for checking whether any form of old tuple was logged */
#define XLH_DELETE_CONTAINS_OLD \
/* "options" flag bits for table_tuple_delete */
#define TABLE_DELETE_CHANGING_PARTITION (1 << 0)
+#define TABLE_DELETE_NO_LOGICAL (1 << 1)
/* "options" flag bits for table_tuple_update */
-/* XXX none at present */
+#define TABLE_UPDATE_NO_LOGICAL (1 << 0)
/* flag bits for table_tuple_lock */
/* Follow tuples whose update is in progress if lock modes don't conflict */
Relation OldIndex,
bool use_sort,
TransactionId OldestXmin,
+ Snapshot snapshot,
TransactionId *xid_cutoff,
MultiXactId *multi_cutoff,
double *num_tuples,
* cmax/cmin if successful)
* options - bitmask of options. No values are currently recognized.
* crosscheck - if not InvalidSnapshot, also check old tuple against this
- * wait - true if should wait for any conflicting update to commit/abort
+ * options - These allow the caller to specify options that may change the
+ * behavior of the AM. The AM will ignore options that it does not support.
+ * TABLE_UPDATE_WAIT -- set if should wait for any conflicting update to
+ * commit/abort
+ * TABLE_UPDATE_NO_LOGICAL -- force-disables the emitting of logical
+ * decoding information for the tuple.
*
* Output parameters:
* slot - newly constructed tuple data to store
* not needed for the relation's AM
* - *xid_cutoff - ditto
* - *multi_cutoff - ditto
+ * - snapshot - if != NULL, ignore data changes done by transactions that this
+ * (MVCC) snapshot considers still in-progress or in the future.
*
* Output parameters:
* - *xid_cutoff - rel's new relfrozenxid value, may be invalid
Relation OldIndex,
bool use_sort,
TransactionId OldestXmin,
+ Snapshot snapshot,
TransactionId *xid_cutoff,
MultiXactId *multi_cutoff,
double *num_tuples,
{
OldTable->rd_tableam->relation_copy_for_cluster(OldTable, NewTable, OldIndex,
use_sort, OldestXmin,
+ snapshot,
xid_cutoff, multi_cutoff,
num_tuples, tups_vacuumed,
tups_recently_dead);
#define PROGRESS_REPACK_PHASE 1
#define PROGRESS_REPACK_INDEX_RELID 2
#define PROGRESS_REPACK_HEAP_TUPLES_SCANNED 3
-#define PROGRESS_REPACK_HEAP_TUPLES_WRITTEN 4
-#define PROGRESS_REPACK_TOTAL_HEAP_BLKS 5
-#define PROGRESS_REPACK_HEAP_BLKS_SCANNED 6
-#define PROGRESS_REPACK_INDEX_REBUILD_COUNT 7
+#define PROGRESS_REPACK_HEAP_TUPLES_INSERTED 4
+#define PROGRESS_REPACK_HEAP_TUPLES_UPDATED 5
+#define PROGRESS_REPACK_HEAP_TUPLES_DELETED 6
+#define PROGRESS_REPACK_TOTAL_HEAP_BLKS 7
+#define PROGRESS_REPACK_HEAP_BLKS_SCANNED 8
+#define PROGRESS_REPACK_INDEX_REBUILD_COUNT 9
/*
* Phases of repack (as advertised via PROGRESS_REPACK_PHASE).
#define PROGRESS_REPACK_PHASE_INDEX_SCAN_HEAP 2
#define PROGRESS_REPACK_PHASE_SORT_TUPLES 3
#define PROGRESS_REPACK_PHASE_WRITE_NEW_HEAP 4
-#define PROGRESS_REPACK_PHASE_SWAP_REL_FILES 5
-#define PROGRESS_REPACK_PHASE_REBUILD_INDEX 6
-#define PROGRESS_REPACK_PHASE_FINAL_CLEANUP 7
+#define PROGRESS_REPACK_PHASE_CATCH_UP 5
+#define PROGRESS_REPACK_PHASE_SWAP_REL_FILES 6
+#define PROGRESS_REPACK_PHASE_REBUILD_INDEX 7
+#define PROGRESS_REPACK_PHASE_FINAL_CLEANUP 8
/* Progress parameters for CREATE INDEX */
/* 3, 4 and 5 reserved for "waitfor" metrics */
#ifndef REPACK_H
#define REPACK_H
+#include <signal.h>
+
#include "nodes/parsenodes.h"
#include "parser/parse_node.h"
#include "storage/lockdefs.h"
#define CLUOPT_RECHECK_ISCLUSTERED 0x04 /* recheck relation state for
* indisclustered */
#define CLUOPT_ANALYZE 0x08 /* do an ANALYZE */
+#define CLUOPT_CONCURRENT 0x10 /* allow concurrent data changes */
/* options for CLUSTER */
typedef struct ClusterParams
uint32 options; /* bitmask of CLUOPT_* */
} ClusterParams;
+extern PGDLLIMPORT volatile sig_atomic_t RepackMessagePending;
+
extern void ExecRepack(ParseState *pstate, RepackStmt *stmt, bool isTopLevel);
extern void cluster_rel(RepackCommand command, Relation OldHeap, Oid indexOid,
- ClusterParams *params);
+ ClusterParams *params, bool isTopLevel);
extern void check_index_is_clusterable(Relation OldHeap, Oid indexOid,
LOCKMODE lockmode);
extern void mark_index_clustered(Relation rel, Oid indexOid, bool is_internal);
bool swap_toast_by_content,
bool check_constraints,
bool is_internal,
+ bool reindex,
TransactionId frozenXid,
MultiXactId cutoffMulti,
char newrelpersistence);
+extern void HandleRepackMessageInterrupt(void);
+extern void ProcessRepackMessages(void);
+
+/* in repack_worker.c */
+extern void RepackWorkerMain(Datum main_arg);
+extern bool AmRepackWorker(void);
+
#endif /* REPACK_H */
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * repack_internal.h
+ * header for REPACK internals
+ *
+ * Copyright (c) 2026, PostgreSQL Global Development Group
+ *
+ * src/include/commands/repack_internal.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef REPACK_INTERNAL_H
+#define REPACK_INTERNAL_H
+
+#include "nodes/execnodes.h"
+#include "replication/decode.h"
+#include "postmaster/bgworker.h"
+#include "replication/logical.h"
+#include "storage/buffile.h"
+#include "storage/sharedfileset.h"
+#include "storage/shm_mq.h"
+#include "utils/resowner.h"
+
+/*
+ * The type of a change stored in the output files.
+ */
+typedef char ConcurrentChangeKind;
+
+#define CHANGE_INSERT 'i'
+#define CHANGE_UPDATE_OLD 'u'
+#define CHANGE_UPDATE_NEW 'U'
+#define CHANGE_DELETE 'd'
+
+/*
+ * Logical decoding state.
+ *
+ * The output plugin uses it to store the data changes that it decodes from
+ * WAL while the table contents is being copied to a new storage.
+ */
+typedef struct RepackDecodingState
+{
+#ifdef USE_ASSERT_CHECKING
+ /* The relation whose changes we're decoding. */
+ Oid relid;
+#endif
+
+ /* Per-change memory context. */
+ MemoryContext change_cxt;
+
+ /* A tuple slot used to pass tuples back and forth */
+ TupleTableSlot *slot;
+
+ /*
+ * Memory context and resource owner of the decoding worker's transaction.
+ */
+ MemoryContext worker_cxt;
+ ResourceOwner worker_resowner;
+
+ /* The current output file. */
+ BufFile *file;
+} RepackDecodingState;
+
+/*
+ * Shared memory used for communication between the backend running REPACK and
+ * the worker that performs logical decoding of data changes.
+ */
+typedef struct DecodingWorkerShared
+{
+ /* Is the decoding initialized? */
+ bool initialized;
+
+ /*
+ * Once the worker has reached this LSN, it should close the current
+ * output file and either create a new one or exit, according to the field
+ * 'done'. If the value is InvalidXLogRecPtr, the worker should decode all
+ * the WAL available and keep checking this field. It is ok if the worker
+ * had already decoded records whose LSN is >= lsn_upto before this field
+ * has been set.
+ */
+ XLogRecPtr lsn_upto;
+
+ /* Exit after closing the current file? */
+ bool done;
+
+ /* The output is stored here. */
+ SharedFileSet sfs;
+
+ /* Number of the last file exported by the worker. */
+ int last_exported;
+
+ /* Synchronize access to the fields above. */
+ slock_t mutex;
+
+ /* Database to connect to. */
+ Oid dbid;
+
+ /* Role to connect as. */
+ Oid roleid;
+
+ /* Relation from which data changes to decode. */
+ Oid relid;
+
+ /* CV the backend waits on */
+ ConditionVariable cv;
+
+ /* Info to signal the backend. */
+ PGPROC *backend_proc;
+ pid_t backend_pid;
+ ProcNumber backend_proc_number;
+ dsm_segment *dsm_seg;
+
+ /*
+ * Memory the queue is located in.
+ *
+ * For considerations on the value see the comments of
+ * PARALLEL_ERROR_QUEUE_SIZE.
+ */
+#define REPACK_ERROR_QUEUE_SIZE 16384
+ char error_queue[FLEXIBLE_ARRAY_MEMBER];
+} DecodingWorkerShared;
+
+extern void DecodingWorkerFileName(char *fname, Oid relid, uint32 seq);
+
+
+#endif /* REPACK_INTERNAL_H */
extern void LogicalDecodingProcessRecord(LogicalDecodingContext *ctx,
XLogReaderState *record);
+/* in commands/repack_worker.c */
+extern bool change_useless_for_repack(XLogRecordBuffer *buf);
+
+
#endif
#define AccessShareLock 1 /* SELECT */
#define RowShareLock 2 /* SELECT FOR UPDATE/FOR SHARE */
#define RowExclusiveLock 3 /* INSERT, UPDATE, DELETE */
-#define ShareUpdateExclusiveLock 4 /* VACUUM (non-FULL), ANALYZE, CREATE
- * INDEX CONCURRENTLY */
+#define ShareUpdateExclusiveLock 4 /* VACUUM (non-exclusive), ANALYZE, CREATE
+ * INDEX CONCURRENTLY, REPACK CONCURRENTLY */
#define ShareLock 5 /* CREATE INDEX (WITHOUT CONCURRENTLY) */
#define ShareRowExclusiveLock 6 /* like EXCLUSIVE MODE, but allows ROW
* SHARE */
PROCSIG_BARRIER, /* global barrier interrupt */
PROCSIG_LOG_MEMORY_CONTEXT, /* ask backend to log the memory contexts */
PROCSIG_PARALLEL_APPLY_MESSAGE, /* Message from parallel apply workers */
+ PROCSIG_REPACK_MESSAGE, /* Message from repack worker */
PROCSIG_RECOVERY_CONFLICT, /* backend is blocking recovery, check
* PGPROC->pendingRecoveryConflicts for the
* reason */
ifeq (,$(findstring conversion_procs,$(subdir)))
ifeq (,$(findstring libpqwalreceiver,$(subdir)))
ifeq (,$(findstring replication/pgoutput,$(subdir)))
+ifeq (,$(findstring replication/pgrepack,$(subdir)))
ifeq (,$(findstring snowball,$(subdir)))
override CPPFLAGS+= -DBUILDING_DLL
endif
endif
endif
endif
+endif
ifneq (,$(findstring src/common,$(subdir)))
override CPPFLAGS+= -DBUILDING_DLL
ifeq (,$(findstring conversion_procs,$(subdir)))
ifeq (,$(findstring libpqwalreceiver,$(subdir)))
ifeq (,$(findstring replication/pgoutput,$(subdir)))
+ifeq (,$(findstring replication/pgrepack,$(subdir)))
ifeq (,$(findstring snowball,$(subdir)))
override CPPFLAGS+= -DBUILDING_DLL
endif
endif
endif
endif
+endif
ifneq (,$(findstring src/common,$(subdir)))
override CPPFLAGS+= -DBUILDING_DLL
ISOLATION = basic \
inplace \
+ repack \
+ repack_toast \
syscache-update-pruned \
heap_lock_update
--- /dev/null
+Parsed test spec with 2 sessions
+
+starting permutation: wait_before_lock change_existing change_new change_subxact1 change_subxact2 check2 wakeup_before_lock check1
+injection_points_attach
+-----------------------
+
+(1 row)
+
+step wait_before_lock:
+ REPACK (CONCURRENTLY) repack_test USING INDEX repack_test_pkey;
+ <waiting ...>
+step change_existing:
+ UPDATE repack_test SET i=10 where i=1;
+ UPDATE repack_test SET j=20 where i=2;
+ UPDATE repack_test SET i=30 where i=3;
+ UPDATE repack_test SET i=40 where i=30;
+ DELETE FROM repack_test WHERE i=4;
+
+step change_new:
+ INSERT INTO repack_test(i, j) VALUES (5, 5), (6, 6), (7, 7), (8, 8);
+ UPDATE repack_test SET i=50 where i=5;
+ UPDATE repack_test SET j=60 where i=6;
+ DELETE FROM repack_test WHERE i=7;
+
+step change_subxact1:
+ BEGIN;
+ INSERT INTO repack_test(i, j) VALUES (100, 100);
+ SAVEPOINT s1;
+ UPDATE repack_test SET i=101 where i=100;
+ SAVEPOINT s2;
+ UPDATE repack_test SET i=102 where i=101;
+ COMMIT;
+
+step change_subxact2:
+ BEGIN;
+ SAVEPOINT s1;
+ INSERT INTO repack_test(i, j) VALUES (110, 110);
+ ROLLBACK TO SAVEPOINT s1;
+ INSERT INTO repack_test(i, j) VALUES (110, 111);
+ COMMIT;
+
+step check2:
+ INSERT INTO relfilenodes(node)
+ SELECT relfilenode FROM pg_class WHERE relname='repack_test';
+
+ SELECT i, j FROM repack_test ORDER BY i, j;
+
+ INSERT INTO data_s2(i, j)
+ SELECT i, j FROM repack_test;
+
+ i| j
+---+---
+ 2| 20
+ 6| 60
+ 8| 8
+ 10| 1
+ 40| 3
+ 50| 5
+102|100
+110|111
+(8 rows)
+
+step wakeup_before_lock:
+ SELECT injection_points_wakeup('repack-concurrently-before-lock');
+
+injection_points_wakeup
+-----------------------
+
+(1 row)
+
+step wait_before_lock: <... completed>
+step check1:
+ INSERT INTO relfilenodes(node)
+ SELECT relfilenode FROM pg_class WHERE relname='repack_test';
+
+ SELECT count(DISTINCT node) FROM relfilenodes;
+
+ SELECT i, j FROM repack_test ORDER BY i, j;
+
+ INSERT INTO data_s1(i, j)
+ SELECT i, j FROM repack_test;
+
+ SELECT count(*)
+ FROM data_s1 d1 FULL JOIN data_s2 d2 USING (i, j)
+ WHERE d1.i ISNULL OR d2.i ISNULL;
+
+count
+-----
+ 2
+(1 row)
+
+ i| j
+---+---
+ 2| 20
+ 6| 60
+ 8| 8
+ 10| 1
+ 40| 3
+ 50| 5
+102|100
+110|111
+(8 rows)
+
+count
+-----
+ 0
+(1 row)
+
+injection_points_detach
+-----------------------
+
+(1 row)
+
--- /dev/null
+Parsed test spec with 2 sessions
+
+starting permutation: wait_before_lock change check2 wakeup_before_lock check1
+injection_points_attach
+-----------------------
+
+(1 row)
+
+step wait_before_lock:
+ REPACK (CONCURRENTLY) repack_test;
+ <waiting ...>
+step change:
+ UPDATE repack_test SET j=get_long_string() where i=2;
+ DELETE FROM repack_test WHERE i=3;
+ INSERT INTO repack_test(i, j) VALUES (4, get_long_string());
+ UPDATE repack_test SET i=3 where i=1;
+
+step check2:
+ INSERT INTO relfilenodes(node)
+ SELECT c2.relfilenode
+ FROM pg_class c1 JOIN pg_class c2 ON c2.oid = c1.oid OR c2.oid = c1.reltoastrelid
+ WHERE c1.relname='repack_test';
+
+ INSERT INTO data_s2(i, j)
+ SELECT i, j FROM repack_test;
+
+step wakeup_before_lock:
+ SELECT injection_points_wakeup('repack-concurrently-before-lock');
+
+injection_points_wakeup
+-----------------------
+
+(1 row)
+
+step wait_before_lock: <... completed>
+step check1:
+ INSERT INTO relfilenodes(node)
+ SELECT c2.relfilenode
+ FROM pg_class c1 JOIN pg_class c2 ON c2.oid = c1.oid OR c2.oid = c1.reltoastrelid
+ WHERE c1.relname='repack_test';
+
+ SELECT count(DISTINCT node) FROM relfilenodes;
+
+ INSERT INTO data_s1(i, j)
+ SELECT i, j FROM repack_test;
+
+ SELECT count(*)
+ FROM data_s1 d1 FULL JOIN data_s2 d2 USING (i, j)
+ WHERE d1.i ISNULL OR d2.i ISNULL;
+
+count
+-----
+ 4
+(1 row)
+
+count
+-----
+ 0
+(1 row)
+
+injection_points_detach
+-----------------------
+
+(1 row)
+
'specs': [
'basic',
'inplace',
+ 'repack',
+ 'repack_toast',
'syscache-update-pruned',
'heap_lock_update',
],
--- /dev/null
+# REPACK (CONCURRENTLY) ... USING INDEX ...;
+setup
+{
+ CREATE EXTENSION injection_points;
+
+ CREATE TABLE repack_test(i int PRIMARY KEY, j int);
+ INSERT INTO repack_test(i, j) VALUES (1, 1), (2, 2), (3, 3), (4, 4);
+
+ CREATE TABLE relfilenodes(node oid);
+
+ CREATE TABLE data_s1(i int, j int);
+ CREATE TABLE data_s2(i int, j int);
+}
+
+teardown
+{
+ DROP TABLE repack_test;
+ DROP EXTENSION injection_points;
+
+ DROP TABLE relfilenodes;
+ DROP TABLE data_s1;
+ DROP TABLE data_s2;
+}
+
+session s1
+setup
+{
+ SELECT injection_points_set_local();
+ SELECT injection_points_attach('repack-concurrently-before-lock', 'wait');
+}
+# Perform the initial load and wait for s2 to do some data changes.
+step wait_before_lock
+{
+ REPACK (CONCURRENTLY) repack_test USING INDEX repack_test_pkey;
+}
+# Check the table from the perspective of s1.
+#
+# Besides the contents, we also check that relfilenode has changed.
+
+# Have each session write the contents into a table and use FULL JOIN to check
+# if the outputs are identical.
+step check1
+{
+ INSERT INTO relfilenodes(node)
+ SELECT relfilenode FROM pg_class WHERE relname='repack_test';
+
+ SELECT count(DISTINCT node) FROM relfilenodes;
+
+ SELECT i, j FROM repack_test ORDER BY i, j;
+
+ INSERT INTO data_s1(i, j)
+ SELECT i, j FROM repack_test;
+
+ SELECT count(*)
+ FROM data_s1 d1 FULL JOIN data_s2 d2 USING (i, j)
+ WHERE d1.i ISNULL OR d2.i ISNULL;
+}
+teardown
+{
+ SELECT injection_points_detach('repack-concurrently-before-lock');
+}
+
+session s2
+# Change the existing data. UPDATE changes both key and non-key columns. Also
+# update one row twice to test whether tuple version generated by this session
+# can be found.
+step change_existing
+{
+ UPDATE repack_test SET i=10 where i=1;
+ UPDATE repack_test SET j=20 where i=2;
+ UPDATE repack_test SET i=30 where i=3;
+ UPDATE repack_test SET i=40 where i=30;
+ DELETE FROM repack_test WHERE i=4;
+}
+# Insert new rows and UPDATE / DELETE some of them. Again, update both key and
+# non-key column.
+step change_new
+{
+ INSERT INTO repack_test(i, j) VALUES (5, 5), (6, 6), (7, 7), (8, 8);
+ UPDATE repack_test SET i=50 where i=5;
+ UPDATE repack_test SET j=60 where i=6;
+ DELETE FROM repack_test WHERE i=7;
+}
+
+# When applying concurrent data changes, we should see the effects of an
+# in-progress subtransaction.
+#
+# XXX Not sure this test is useful now - it was designed for the patch that
+# preserves tuple visibility and which therefore modifies
+# TransactionIdIsCurrentTransactionId().
+step change_subxact1
+{
+ BEGIN;
+ INSERT INTO repack_test(i, j) VALUES (100, 100);
+ SAVEPOINT s1;
+ UPDATE repack_test SET i=101 where i=100;
+ SAVEPOINT s2;
+ UPDATE repack_test SET i=102 where i=101;
+ COMMIT;
+}
+
+# When applying concurrent data changes, we should not see the effects of a
+# rolled back subtransaction.
+#
+# XXX Is this test useful? See above.
+step change_subxact2
+{
+ BEGIN;
+ SAVEPOINT s1;
+ INSERT INTO repack_test(i, j) VALUES (110, 110);
+ ROLLBACK TO SAVEPOINT s1;
+ INSERT INTO repack_test(i, j) VALUES (110, 111);
+ COMMIT;
+}
+
+# Check the table from the perspective of s2.
+step check2
+{
+ INSERT INTO relfilenodes(node)
+ SELECT relfilenode FROM pg_class WHERE relname='repack_test';
+
+ SELECT i, j FROM repack_test ORDER BY i, j;
+
+ INSERT INTO data_s2(i, j)
+ SELECT i, j FROM repack_test;
+}
+step wakeup_before_lock
+{
+ SELECT injection_points_wakeup('repack-concurrently-before-lock');
+}
+
+# Test if data changes introduced while one session is performing REPACK
+# CONCURRENTLY find their way into the table.
+permutation
+ wait_before_lock
+ change_existing
+ change_new
+ change_subxact1
+ change_subxact2
+ check2
+ wakeup_before_lock
+ check1
--- /dev/null
+# REPACK (CONCURRENTLY);
+#
+# Test handling of TOAST. At the same time, no tuplesort.
+setup
+{
+ CREATE EXTENSION injection_points;
+
+ -- Return a string that needs to be TOASTed.
+ CREATE FUNCTION get_long_string()
+ RETURNS text
+ LANGUAGE sql as $$
+ SELECT string_agg(chr(65 + trunc(25 * random())::int), '')
+ FROM generate_series(1, 2048) s(x);
+ $$;
+
+ CREATE TABLE repack_test(i int PRIMARY KEY, j text);
+ INSERT INTO repack_test(i, j) VALUES (1, get_long_string()),
+ (2, get_long_string()), (3, get_long_string());
+
+ CREATE TABLE relfilenodes(node oid);
+
+ CREATE TABLE data_s1(i int, j text);
+ CREATE TABLE data_s2(i int, j text);
+}
+
+teardown
+{
+ DROP TABLE repack_test;
+ DROP EXTENSION injection_points;
+ DROP FUNCTION get_long_string();
+
+ DROP TABLE relfilenodes;
+ DROP TABLE data_s1;
+ DROP TABLE data_s2;
+}
+
+session s1
+setup
+{
+ SELECT injection_points_set_local();
+ SELECT injection_points_attach('repack-concurrently-before-lock', 'wait');
+}
+# Perform the initial load and wait for s2 to do some data changes.
+step wait_before_lock
+{
+ REPACK (CONCURRENTLY) repack_test;
+}
+# Check the table from the perspective of s1.
+#
+# Besides the contents, we also check that relfilenode has changed.
+
+# Have each session write the contents into a table and use FULL JOIN to check
+# if the outputs are identical.
+step check1
+{
+ INSERT INTO relfilenodes(node)
+ SELECT c2.relfilenode
+ FROM pg_class c1 JOIN pg_class c2 ON c2.oid = c1.oid OR c2.oid = c1.reltoastrelid
+ WHERE c1.relname='repack_test';
+
+ SELECT count(DISTINCT node) FROM relfilenodes;
+
+ INSERT INTO data_s1(i, j)
+ SELECT i, j FROM repack_test;
+
+ SELECT count(*)
+ FROM data_s1 d1 FULL JOIN data_s2 d2 USING (i, j)
+ WHERE d1.i ISNULL OR d2.i ISNULL;
+}
+teardown
+{
+ SELECT injection_points_detach('repack-concurrently-before-lock');
+}
+
+session s2
+step change
+# Separately test UPDATE of both plain ("i") and TOASTed ("j") attribute. In
+# the first case, the new tuple we get from reorderbuffer.c contains "j" as a
+# TOAST pointer, which we need to update so it points to the new heap. In the
+# latter case, we receive "j" as "external indirect" value - here we test that
+# the decoding worker writes the tuple to a file correctly and that the
+# backend executing REPACK manages to restore it.
+{
+ UPDATE repack_test SET j=get_long_string() where i=2;
+ DELETE FROM repack_test WHERE i=3;
+ INSERT INTO repack_test(i, j) VALUES (4, get_long_string());
+ UPDATE repack_test SET i=3 where i=1;
+}
+# Check the table from the perspective of s2.
+step check2
+{
+ INSERT INTO relfilenodes(node)
+ SELECT c2.relfilenode
+ FROM pg_class c1 JOIN pg_class c2 ON c2.oid = c1.oid OR c2.oid = c1.reltoastrelid
+ WHERE c1.relname='repack_test';
+
+ INSERT INTO data_s2(i, j)
+ SELECT i, j FROM repack_test;
+}
+step wakeup_before_lock
+{
+ SELECT injection_points_wakeup('repack-concurrently-before-lock');
+}
+
+# Test if data changes introduced while one session is performing REPACK
+# CONCURRENTLY find their way into the table.
+permutation
+ wait_before_lock
+ change
+ check2
+ wakeup_before_lock
+ check1
clstrpart33 | 2 | r | f
(7 rows)
+-- CONCURRENTLY doesn't like partitioned tables
+REPACK (CONCURRENTLY) clstrpart;
+ERROR: REPACK (CONCURRENTLY) is not supported for partitioned tables
+HINT: Consider running the command on individual partitions.
DROP TABLE clstrpart;
-- Ownership of partitions is checked
CREATE TABLE ptnowner(i int unique) PARTITION BY LIST (i);
clstr_3
(2 rows)
+-- concurrently
+REPACK (CONCURRENTLY) pg_class;
+ERROR: cannot repack relation "pg_class"
+HINT: REPACK CONCURRENTLY is not supported for catalog relations.
-- clean up
DROP TABLE clustertest;
DROP TABLE clstr_1;
phase,
repack_index_relid AS cluster_index_relid,
heap_tuples_scanned,
- heap_tuples_written,
+ (heap_tuples_inserted + heap_tuples_updated) AS heap_tuples_written,
heap_blks_total,
heap_blks_scanned,
index_rebuild_count
WHEN 2 THEN 'index scanning heap'::text
WHEN 3 THEN 'sorting tuples'::text
WHEN 4 THEN 'writing new heap'::text
- WHEN 5 THEN 'swapping relation files'::text
- WHEN 6 THEN 'rebuilding index'::text
- WHEN 7 THEN 'performing final cleanup'::text
+ WHEN 5 THEN 'catch-up'::text
+ WHEN 6 THEN 'swapping relation files'::text
+ WHEN 7 THEN 'rebuilding index'::text
+ WHEN 8 THEN 'performing final cleanup'::text
ELSE NULL::text
END AS phase,
(s.param3)::oid AS repack_index_relid,
s.param4 AS heap_tuples_scanned,
- s.param5 AS heap_tuples_written,
- s.param6 AS heap_blks_total,
- s.param7 AS heap_blks_scanned,
- s.param8 AS index_rebuild_count
+ s.param5 AS heap_tuples_inserted,
+ s.param6 AS heap_tuples_updated,
+ s.param7 AS heap_tuples_deleted,
+ s.param8 AS heap_blks_total,
+ s.param9 AS heap_blks_scanned,
+ s.param10 AS index_rebuild_count
FROM (pg_stat_get_progress_info('REPACK'::text) s(pid, datid, relid, param1, param2, param3, param4, param5, param6, param7, param8, param9, param10, param11, param12, param13, param14, param15, param16, param17, param18, param19, param20)
LEFT JOIN pg_database d ON ((s.datid = d.oid)));
pg_stat_progress_vacuum| SELECT s.pid,
CREATE TEMP TABLE new_cluster_info AS SELECT relname, level, relfilenode, relkind FROM pg_partition_tree('clstrpart'::regclass) AS tree JOIN pg_class c ON c.oid=tree.relid ;
SELECT relname, old.level, old.relkind, old.relfilenode = new.relfilenode FROM old_cluster_info AS old JOIN new_cluster_info AS new USING (relname) ORDER BY relname COLLATE "C";
+-- CONCURRENTLY doesn't like partitioned tables
+REPACK (CONCURRENTLY) clstrpart;
+
DROP TABLE clstrpart;
-- Ownership of partitions is checked
WHERE o.relfilenode <> n.relfilenode
ORDER BY o.relname;
+-- concurrently
+REPACK (CONCURRENTLY) pg_class;
+
-- clean up
DROP TABLE clustertest;
DROP TABLE clstr_1;
CatalogId
CatalogIdMapEntry
CatalogIndexState
+ChangeContext
ChangeVarNodes_callback
ChangeVarNodes_context
ChannelName
CompressionLocation
CompressorState
ComputeXidHorizonsResult
+ConcurrentChangeKind
ConditionVariable
ConditionVariableMinimallyPadded
ConditionalStack
DecodedBkpBlock
DecodedXLogRecord
DecodingOutputState
+DecodingWorker
+DecodingWorkerShared
DefElem
DefElemAction
DefaultACLInfo
IndexFetchHeapData
IndexFetchTableData
IndexInfo
+IndexInsertState
IndexList
IndexOnlyScan
IndexOnlyScanState
ReorderBufferUpdateProgressTxnCB
ReorderTuple
RepackCommand
+RepackDecodingState
RepackStmt
ReparameterizeForeignPathByChild_function
ReplOriginId
projects / thirdparty / postgresql.git / commitdiff
