Remove unneeded old_rel_pages VACUUM state field.

The field hasn't been used since commit 3d351d91, which redefined
pg_class.reltuples to be -1 before the first VACUUM or ANALYZE.

Also rename a local variable of the same name ("old_rel_pages"). This is
used by relation truncation to represent the original relation size at
the start of the ongoing VACUUM operation.  Rename it to orig_rel_pages,
since that's a lot clearer.  (This name matches similar nearby code.)

diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c
index 2589f80a52fa4424692c67f08765de404cb5212c..19d8276de2c8bf59ef172c392bbcc7031e102da7 100644 (file)
--- a/src/backend/access/heap/vacuumlazy.c
+++ b/src/backend/access/heap/vacuumlazy.c
@@ -323,12 +323,10 @@ typedef struct LVRelState
        BufferAccessStrategy bstrategy;
        LVParallelState *lps;
 
-       /* Statistics from pg_class when we start out */
-       BlockNumber old_rel_pages;      /* previous value of pg_class.relpages */
-       double          old_live_tuples;        /* previous value of pg_class.reltuples */
        /* rel's initial relfrozenxid and relminmxid */
        TransactionId relfrozenxid;
        MultiXactId relminmxid;
+       double          old_live_tuples;        /* previous value of pg_class.reltuples */
 
        /* VACUUM operation's cutoff for pruning */
        TransactionId OldestXmin;
@@ -593,10 +591,9 @@ heap_vacuum_rel(Relation rel, VacuumParams *params,
        }
 
        vacrel->bstrategy = bstrategy;
-       vacrel->old_rel_pages = rel->rd_rel->relpages;
-       vacrel->old_live_tuples = rel->rd_rel->reltuples;
        vacrel->relfrozenxid = rel->rd_rel->relfrozenxid;
        vacrel->relminmxid = rel->rd_rel->relminmxid;
+       vacrel->old_live_tuples = rel->rd_rel->reltuples;
 
        /* Set cutoffs for entire VACUUM */
        vacrel->OldestXmin = OldestXmin;
@@ -3182,7 +3179,7 @@ should_attempt_truncation(LVRelState *vacrel)
 static void
 lazy_truncate_heap(LVRelState *vacrel)
 {
-       BlockNumber old_rel_pages = vacrel->rel_pages;
+       BlockNumber orig_rel_pages = vacrel->rel_pages;
        BlockNumber new_rel_pages;
        bool            lock_waiter_detected;
        int                     lock_retry;
@@ -3246,7 +3243,7 @@ lazy_truncate_heap(LVRelState *vacrel)
                 * the newly added pages presumably contain non-deletable tuples.
                 */
                new_rel_pages = RelationGetNumberOfBlocks(vacrel->rel);
-               if (new_rel_pages != old_rel_pages)
+               if (new_rel_pages != orig_rel_pages)
                {
                        /*
                         * Note: we intentionally don't update vacrel->rel_pages with the
@@ -3268,7 +3265,7 @@ lazy_truncate_heap(LVRelState *vacrel)
                new_rel_pages = count_nondeletable_pages(vacrel, &lock_waiter_detected);
                vacrel->blkno = new_rel_pages;
 
-               if (new_rel_pages >= old_rel_pages)
+               if (new_rel_pages >= orig_rel_pages)
                {
                        /* can't do anything after all */
                        UnlockRelation(vacrel->rel, AccessExclusiveLock);
@@ -3294,16 +3291,16 @@ lazy_truncate_heap(LVRelState *vacrel)
                 * without also touching reltuples, since the tuple count wasn't
                 * changed by the truncation.
                 */
-               vacrel->pages_removed += old_rel_pages - new_rel_pages;
+               vacrel->pages_removed += orig_rel_pages - new_rel_pages;
                vacrel->rel_pages = new_rel_pages;
 
                ereport(elevel,
                                (errmsg("\"%s\": truncated %u to %u pages",
                                                vacrel->relname,
-                                               old_rel_pages, new_rel_pages),
+                                               orig_rel_pages, new_rel_pages),
                                 errdetail_internal("%s",
                                                                        pg_rusage_show(&ru0))));
-               old_rel_pages = new_rel_pages;
+               orig_rel_pages = new_rel_pages;
        } while (new_rel_pages > vacrel->nonempty_pages && lock_waiter_detected);
 }