From: Andres Freund <andres@anarazel.de>
Date: Thu, 18 Sep 2025 00:28:43 +0000 (-0400)
Subject: Mark shared buffer lookup table HASH_FIXED_SIZE
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0110e2ec5c0f230beb439885bd1f8505e783e742;p=thirdparty%2Fpostgresql.git

Mark shared buffer lookup table HASH_FIXED_SIZE

StrategyInitialize() calls InitBufTable() with maximum number of entries that
the buffer lookup table can ever have. Thus there should not be any need to
allocate more element after initialization. Hence mark the hash table as fixed
sized.

Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://postgr.es/m/CAExHW5v0jh3F_wj86yC=qBfWk0uiT94qy=Z41uzAHLHh0SerRA@mail.gmail.com
---

diff --git a/src/backend/storage/buffer/buf_table.c b/src/backend/storage/buffer/buf_table.c
index a50955d5286..9d256559bab 100644
--- a/src/backend/storage/buffer/buf_table.c
+++ b/src/backend/storage/buffer/buf_table.c
@@ -62,7 +62,7 @@ InitBufTable(int size)
 	SharedBufHash = ShmemInitHash("Shared Buffer Lookup Table",
 								  size, size,
 								  &info,
-								  HASH_ELEM | HASH_BLOBS | HASH_PARTITION);
+								  HASH_ELEM | HASH_BLOBS | HASH_PARTITION | HASH_FIXED_SIZE);
 }
 
 /*