pg_upgrade: Use COPY for LO metadata for upgrades from < v12.

Before v12, pg_largeobject_metadata was defined WITH OIDS, so
unlike newer versions, the "oid" column was a hidden system column
that pg_dump's getTableAttrs() will not pick up.  Thus, for commit
161a3e8b68, we did not bother trying to use COPY for
pg_largeobject_metadata for upgrades from older versions.  This
commit removes that restriction by adjusting the query in
getTableAttrs() to pick up the "oid" system column and by teaching
dumpTableData_copy() to use COPY (SELECT ...) for this catalog,
since system columns cannot be used in COPY's column list.

Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/aYzuAz_ITUpd9ZvH%40nathan

diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index 9007f7a0c431aee04972d8125956cfe42909e8a9..7afcc0859c868ca480527e7668cbd078c8a46746 100644 (file)
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -2991,12 +2991,9 @@ _tocEntryRequired(TocEntry *te, teSection curSection, ArchiveHandle *AH)
        /*
         * For binary upgrade mode, dump pg_largeobject_metadata and the
         * associated pg_shdepend rows. This is faster to restore than the
-        * equivalent set of large object commands.  We can only do this for
-        * upgrades from v12 and newer; in older versions, pg_largeobject_metadata
-        * was created WITH OIDS, so the OID column is hidden and won't be dumped.
+        * equivalent set of large object commands.
         */
-       if (ropt->binary_upgrade && AH->public.remoteVersion >= 120000 &&
-               strcmp(te->desc, "TABLE DATA") == 0 &&
+       if (ropt->binary_upgrade && strcmp(te->desc, "TABLE DATA") == 0 &&
                (te->catalogId.oid == LargeObjectMetadataRelationId ||
                 te->catalogId.oid == SharedDependRelationId))
                return REQ_DATA;

diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index b4b7c234e206987c57e3a7e35e3152cc931d20c3..49598304335beb665bc613fc6ec3e77424f4c970 100644 (file)
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -1118,11 +1118,9 @@ main(int argc, char **argv)
         * For binary upgrade mode, dump the pg_shdepend rows for large objects
         * and maybe even pg_largeobject_metadata (see comment below for details).
         * This is faster to restore than the equivalent set of large object
-        * commands.  We can only do this for upgrades from v12 and newer; in
-        * older versions, pg_largeobject_metadata was created WITH OIDS, so the
-        * OID column is hidden and won't be dumped.
+        * commands.
         */
-       if (dopt.binary_upgrade && fout->remoteVersion >= 120000)
+       if (dopt.binary_upgrade)
        {
                TableInfo  *shdepend;
 
@@ -2406,11 +2404,14 @@ dumpTableData_copy(Archive *fout, const void *dcontext)
        column_list = fmtCopyColumnList(tbinfo, clistBuf);
 
        /*
-        * Use COPY (SELECT ...) TO when dumping a foreign table's data, and when
-        * a filter condition was specified.  For other cases a simple COPY
-        * suffices.
+        * Use COPY (SELECT ...) TO when dumping a foreign table's data, when a
+        * filter condition was specified, and when in binary upgrade mode and
+        * dumping an old pg_largeobject_metadata defined WITH OIDS.  For other
+        * cases a simple COPY suffices.
         */
-       if (tdinfo->filtercond || tbinfo->relkind == RELKIND_FOREIGN_TABLE)
+       if (tdinfo->filtercond || tbinfo->relkind == RELKIND_FOREIGN_TABLE ||
+               (fout->dopt->binary_upgrade && fout->remoteVersion < 120000 &&
+                tbinfo->dobj.catId.oid == LargeObjectMetadataRelationId))
        {
                /* Temporary allows to access to foreign tables to dump data */
                if (tbinfo->relkind == RELKIND_FOREIGN_TABLE)
@@ -3967,14 +3968,13 @@ getLOs(Archive *fout)
                                                 "FROM pg_largeobject_metadata ");
 
        /*
-        * For binary upgrades from v12 or newer, we transfer
-        * pg_largeobject_metadata via COPY or by copying/linking its files from
-        * the old cluster.  On such upgrades, we only need to consider large
-        * objects that have comments or security labels, since we still restore
-        * those objects via COMMENT/SECURITY LABEL commands.
+        * For binary upgrades, we transfer pg_largeobject_metadata via COPY or by
+        * copying/linking its files from the old cluster.  On such upgrades, we
+        * only need to consider large objects that have comments or security
+        * labels, since we still restore those objects via COMMENT/SECURITY LABEL
+        * commands.
         */
-       if (dopt->binary_upgrade &&
-               fout->remoteVersion >= 120000)
+       if (dopt->binary_upgrade)
                appendPQExpBufferStr(loQry,
                                                         "WHERE oid IN "
                                                         "(SELECT objoid FROM pg_description "
@@ -4063,25 +4063,13 @@ getLOs(Archive *fout)
                        loinfo->dobj.components |= DUMP_COMPONENT_ACL;
 
                /*
-                * In binary-upgrade mode for LOs, we do *not* dump out the LO data,
-                * as it will be copied by pg_upgrade, which simply copies the
-                * pg_largeobject table.
-                *
-                * The story for LO metadata is more complicated.  For upgrades from
-                * versions older than v12, we use ordinary SQL commands to restore
-                * both the content of pg_largeobject_metadata and any associated
-                * pg_shdepend rows.  For upgrades from newer versions, we transfer
-                * this information via COPY or by copying/linking the files from the
-                * old cluster.  For such upgrades, we do not need to dump the data,
-                * ACLs, or definitions of large objects.
+                * In binary upgrade mode, pg_largeobject and pg_largeobject_metadata
+                * are transferred via COPY or by copying/linking the files from the
+                * old cluster.  Thus, we do not need to dump LO data, definitions, or
+                * ACLs.
                 */
                if (dopt->binary_upgrade)
-               {
-                       if (fout->remoteVersion >= 120000)
-                               loinfo->dobj.dump &= ~(DUMP_COMPONENT_DATA | DUMP_COMPONENT_ACL | DUMP_COMPONENT_DEFINITION);
-                       else
-                               loinfo->dobj.dump &= ~DUMP_COMPONENT_DATA;
-               }
+                       loinfo->dobj.dump &= ~(DUMP_COMPONENT_DATA | DUMP_COMPONENT_ACL | DUMP_COMPONENT_DEFINITION);
 
                /*
                 * Create a "BLOBS" data item for the group, too. This is just a
@@ -9296,12 +9284,10 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
                 * pg_shdepend so that the columns names are collected for the
                 * corresponding COPY commands.  Restoring the data for those catalogs
                 * is faster than restoring the equivalent set of large object
-                * commands.  We can only do this for upgrades from v12 and newer; in
-                * older versions, pg_largeobject_metadata was created WITH OIDS, so
-                * the OID column is hidden and won't be dumped.
+                * commands.
                 */
                if (!tbinfo->interesting &&
-                       !(fout->dopt->binary_upgrade && fout->remoteVersion >= 120000 &&
+                       !(fout->dopt->binary_upgrade &&
                          (tbinfo->dobj.catId.oid == LargeObjectMetadataRelationId ||
                           tbinfo->dobj.catId.oid == SharedDependRelationId)))
                        continue;
@@ -9442,7 +9428,18 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
                                                         "(pt.classoid = co.tableoid AND pt.objoid = co.oid)\n");
 
        appendPQExpBufferStr(q,
-                                                "WHERE a.attnum > 0::pg_catalog.int2\n"
+                                                "WHERE a.attnum > 0::pg_catalog.int2\n");
+
+       /*
+        * For binary upgrades from <v12, be sure to pick up
+        * pg_largeobject_metadata's oid column.
+        */
+       if (fout->dopt->binary_upgrade && fout->remoteVersion < 120000)
+               appendPQExpBufferStr(q,
+                                                        "OR (a.attnum = -2::pg_catalog.int2 AND src.tbloid = "
+                                                        CppAsString2(LargeObjectMetadataRelationId) ")\n");
+
+       appendPQExpBufferStr(q,
                                                 "ORDER BY a.attrelid, a.attnum");
 
        res = ExecuteSqlQuery(fout, q->data, PGRES_TUPLES_OK);
@@ -9510,7 +9507,7 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
                /* cross-check that we only got requested tables */
                if (tbinfo->relkind == RELKIND_SEQUENCE ||
                        (!tbinfo->interesting &&
-                        !(fout->dopt->binary_upgrade && fout->remoteVersion >= 120000 &&
+                        !(fout->dopt->binary_upgrade &&
                           (tbinfo->dobj.catId.oid == LargeObjectMetadataRelationId ||
                                tbinfo->dobj.catId.oid == SharedDependRelationId))))
                        pg_fatal("unexpected column data for table \"%s\"",
@@ -9544,7 +9541,9 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
 
                for (int j = 0; j < numatts; j++, r++)
                {
-                       if (j + 1 != atoi(PQgetvalue(res, r, i_attnum)))
+                       if (j + 1 != atoi(PQgetvalue(res, r, i_attnum)) &&
+                               !(fout->dopt->binary_upgrade && fout->remoteVersion < 120000 &&
+                                 tbinfo->dobj.catId.oid == LargeObjectMetadataRelationId))
                                pg_fatal("invalid column numbering in table \"%s\"",
                                                 tbinfo->dobj.name);
                        tbinfo->attnames[j] = pg_strdup(PQgetvalue(res, r, i_attname));