From 7b47b59d89bf3edaeb11c4ffe3660f3d5b7b86de Mon Sep 17 00:00:00 2001 From: Claudio Freire Date: Fri, 2 Sep 2016 23:21:01 -0300 Subject: [PATCH 1/2] Vacuum: allow using more than 1GB work mem Turns the palloc for dead_tuples into a huge allocation to allow using more than 1GB worth of dead_tuples, saving index scans on heavily bloated tables --- src/backend/commands/vacuumlazy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c index 231e92d..2c98da4 100644 --- a/src/backend/commands/vacuumlazy.c +++ b/src/backend/commands/vacuumlazy.c @@ -1952,7 +1952,7 @@ lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks) { maxtuples = (vac_work_mem * 1024L) / sizeof(ItemPointerData); maxtuples = Min(maxtuples, INT_MAX); - maxtuples = Min(maxtuples, MaxAllocSize / sizeof(ItemPointerData)); + maxtuples = Min(maxtuples, MaxAllocHugeSize / sizeof(ItemPointerData)); /* curious coding here to ensure the multiplication can't overflow */ if ((BlockNumber) (maxtuples / LAZY_ALLOC_TUPLES) > relblocks) @@ -1969,7 +1969,7 @@ lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks) vacrelstats->num_dead_tuples = 0; vacrelstats->max_dead_tuples = (int) maxtuples; vacrelstats->dead_tuples = (ItemPointer) - palloc(maxtuples * sizeof(ItemPointerData)); + MemoryContextAllocHuge(CurrentMemoryContext, maxtuples * sizeof(ItemPointerData)); } /* -- 2.6.6