From 771cfe22a0982f8716abfa253707e74fbbad873a Mon Sep 17 00:00:00 2001 From: Masahiko Sawada Date: Mon, 6 Oct 2025 14:02:01 -0700 Subject: Avoid unnecessary GinFormTuple() calls for incompressible posting lists. Previously, we attempted to form a posting list tuple even when ginCompressPostingList() failed to compress the posting list due to its size. While there was no functional failure, it always wasted one GinFormTuple() call when item pointers didn't fit in a posting list tuple. This commit ensures that a GIN index tuple is formed only when all item pointers in the posting list are successfully compressed. Author: Arseniy Mukhin Reviewed-by: Masahiko Sawada Discussion: https://postgr.es/m/CAE7r3M+C=jcpTD93f_RBHrQp3C+=TAXFs+k4tTuZuuxboK8AvA@mail.gmail.com --- src/backend/access/gin/gininsert.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) (limited to 'src/backend/access') diff --git a/src/backend/access/gin/gininsert.c b/src/backend/access/gin/gininsert.c index e9d4b27427e..1d3ab22556d 100644 --- a/src/backend/access/gin/gininsert.c +++ b/src/backend/access/gin/gininsert.c @@ -218,7 +218,8 @@ addItemPointersToLeafTuple(GinState *ginstate, ItemPointerData *newItems, *oldItems; int oldNPosting, - newNPosting; + newNPosting, + nwritten; GinPostingList *compressedList; Assert(!GinIsPostingTree(old)); @@ -235,18 +236,19 @@ addItemPointersToLeafTuple(GinState *ginstate, /* Compress the posting list, and try to a build tuple with room for it */ res = NULL; - compressedList = ginCompressPostingList(newItems, newNPosting, GinMaxItemSize, - NULL); - pfree(newItems); - if (compressedList) + compressedList = ginCompressPostingList(newItems, newNPosting, GinMaxItemSize, &nwritten); + if (nwritten == newNPosting) { res = GinFormTuple(ginstate, attnum, key, category, (char *) compressedList, SizeOfGinPostingList(compressedList), newNPosting, false); - pfree(compressedList); } + + pfree(newItems); + pfree(compressedList); + if (!res) { /* posting list would be too big, convert to posting tree */ @@ -293,17 +295,19 @@ buildFreshLeafTuple(GinState *ginstate, { IndexTuple res = NULL; GinPostingList *compressedList; + int nwritten; /* try to build a posting list tuple with all the items */ - compressedList = ginCompressPostingList(items, nitem, GinMaxItemSize, NULL); - if (compressedList) + compressedList = ginCompressPostingList(items, nitem, GinMaxItemSize, &nwritten); + if (nwritten == nitem) { res = GinFormTuple(ginstate, attnum, key, category, (char *) compressedList, SizeOfGinPostingList(compressedList), nitem, false); - pfree(compressedList); } + pfree(compressedList); + if (!res) { /* posting list would be too big, build posting tree */ -- cgit v1.2.3