diff options
Diffstat (limited to 'src/backend/access/heap/pruneheap.c')
| -rw-r--r-- | src/backend/access/heap/pruneheap.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/src/backend/access/heap/pruneheap.c b/src/backend/access/heap/pruneheap.c index 3cdfc5b7f1b..869d82ad667 100644 --- a/src/backend/access/heap/pruneheap.c +++ b/src/backend/access/heap/pruneheap.c @@ -325,6 +325,8 @@ heap_page_prune_opt(Relation relation, Buffer buffer) * * cutoffs contains the freeze cutoffs, established by VACUUM at the beginning * of vacuuming the relation. Required if HEAP_PRUNE_FREEZE option is set. + * cutoffs->OldestXmin is also used to determine if dead tuples are + * HEAPTUPLE_RECENTLY_DEAD or HEAPTUPLE_DEAD. * * presult contains output parameters needed by callers, such as the number of * tuples removed and the offsets of dead items on the page after pruning. @@ -922,8 +924,27 @@ heap_prune_satisfies_vacuum(PruneState *prstate, HeapTuple tup, Buffer buffer) if (res != HEAPTUPLE_RECENTLY_DEAD) return res; + /* + * For VACUUM, we must be sure to prune tuples with xmax older than + * OldestXmin -- a visibility cutoff determined at the beginning of + * vacuuming the relation. OldestXmin is used for freezing determination + * and we cannot freeze dead tuples' xmaxes. + */ + if (prstate->cutoffs && + TransactionIdIsValid(prstate->cutoffs->OldestXmin) && + NormalTransactionIdPrecedes(dead_after, prstate->cutoffs->OldestXmin)) + return HEAPTUPLE_DEAD; + + /* + * Determine whether or not the tuple is considered dead when compared + * with the provided GlobalVisState. On-access pruning does not provide + * VacuumCutoffs. And for vacuum, even if the tuple's xmax is not older + * than OldestXmin, GlobalVisTestIsRemovableXid() could find the row dead + * if the GlobalVisState has been updated since the beginning of vacuuming + * the relation. + */ if (GlobalVisTestIsRemovableXid(prstate->vistest, dead_after)) - res = HEAPTUPLE_DEAD; + return HEAPTUPLE_DEAD; return res; } |