From: Heikki Linnakangas Date: Thu, 18 Dec 2025 13:08:48 +0000 (+0200) Subject: Do not emit WAL for unlogged BRIN indexes X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a5277700e47862e9f83b0695fb34ffff0ea2fa34;p=thirdparty%2Fpostgresql.git Do not emit WAL for unlogged BRIN indexes Operations on unlogged relations should not be WAL-logged. The brin_initialize_empty_new_buffer() function didn't get the memo. The function is only called when a concurrent update to a brin page uses up space that we're just about to insert to, which makes it pretty hard to hit. If you do manage to hit it, a full-page WAL record is erroneously emitted for the unlogged index. If you then crash, crash recovery will fail on that record with an error like this: FATAL: could not create file "base/5/32819": File exists Author: Kirill Reshke Discussion: https://www.postgresql.org/message-id/CALdSSPhpZXVFnWjwEBNcySx_vXtXHwB2g99gE6rK0uRJm-3GgQ@mail.gmail.com Backpatch-through: 14 --- diff --git a/src/backend/access/brin/brin_pageops.c b/src/backend/access/brin/brin_pageops.c index b578d259545..27eb2f62ad6 100644 --- a/src/backend/access/brin/brin_pageops.c +++ b/src/backend/access/brin/brin_pageops.c @@ -894,7 +894,11 @@ brin_initialize_empty_new_buffer(Relation idxrel, Buffer buffer) page = BufferGetPage(buffer); brin_page_init(page, BRIN_PAGETYPE_REGULAR); MarkBufferDirty(buffer); - log_newpage_buffer(buffer, true); + + /* XLOG stuff */ + if (RelationNeedsWAL(idxrel)) + log_newpage_buffer(buffer, true); + END_CRIT_SECTION(); /*