diff options
Diffstat (limited to 'src/backend/access/heap')
| -rw-r--r-- | src/backend/access/heap/pruneheap.c | 4 | ||||
| -rw-r--r-- | src/backend/access/heap/vacuumlazy.c | 11 |
2 files changed, 11 insertions, 4 deletions
diff --git a/src/backend/access/heap/pruneheap.c b/src/backend/access/heap/pruneheap.c index 4656f1b3db4..98d31de0031 100644 --- a/src/backend/access/heap/pruneheap.c +++ b/src/backend/access/heap/pruneheap.c @@ -244,7 +244,9 @@ heap_page_prune_opt(Relation relation, Buffer buffer) * Prune and repair fragmentation in the specified page. * * Caller must have pin and buffer cleanup lock on the page. Note that we - * don't update the FSM information for page on caller's behalf. + * don't update the FSM information for page on caller's behalf. Caller might + * also need to account for a reduction in the length of the line pointer + * array following array truncation by us. * * vistest is used to distinguish whether tuples are DEAD or RECENTLY_DEAD * (see heap_prune_satisfies_vacuum and diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c index 092b739dda9..e1cac74e620 100644 --- a/src/backend/access/heap/vacuumlazy.c +++ b/src/backend/access/heap/vacuumlazy.c @@ -223,7 +223,7 @@ typedef struct LVRelState */ typedef struct LVPagePruneState { - bool hastup; /* Page is truncatable? */ + bool hastup; /* Page prevents rel truncation? */ bool has_lpdead_items; /* includes existing LP_DEAD items */ /* @@ -1393,7 +1393,7 @@ lazy_scan_skip(LVRelState *vacrel, Buffer *vmbuffer, BlockNumber next_block, * * It's necessary to consider new pages as a special case, since the rules for * maintaining the visibility map and FSM with empty pages are a little - * different (though new pages can be truncated based on the usual rules). + * different (though new pages can be truncated away during rel truncation). * * Empty pages are not really a special case -- they're just heap pages that * have no allocated tuples (including even LP_UNUSED items). You might @@ -1561,6 +1561,11 @@ lazy_scan_prune(LVRelState *vacrel, Assert(BufferGetBlockNumber(buf) == blkno); + /* + * maxoff might be reduced following line pointer array truncation in + * heap_page_prune. That's safe for us to ignore, since the reclaimed + * space will continue to look like LP_UNUSED items below. + */ maxoff = PageGetMaxOffsetNumber(page); retry: @@ -1768,7 +1773,7 @@ retry: * Check tuple left behind after pruning to see if needs to be frozen * now. */ - prunestate->hastup = true; /* page won't be truncatable */ + prunestate->hastup = true; /* page makes rel truncation unsafe */ if (heap_prepare_freeze_tuple(tuple.t_data, vacrel->relfrozenxid, vacrel->relminmxid, |