From 0256405dba245baa90c3fe35ee69e3cb1ce6253e Mon Sep 17 00:00:00 2001 From: Nathan Bossart Date: Mon, 31 Mar 2025 10:44:26 -0500 Subject: [PATCH v12n 1/3] Skip second WriteToc() for custom-format dumps without data. Presently, "pg_dump --format=custom" calls WriteToc() twice. The second call is intended to update the data offset information, which allegedly makes parallel pg_restore significantly faster. However, if we aren't dumping any data, this step accomplishes nothing and can be skipped. This is a preparatory optimization for a follow-up commit that will move the queries for per-attribute statistics to WriteToc() to save memory. Discussion: https://postgr.es/m/Z9c1rbzZegYQTOQE%40nathan --- src/bin/pg_dump/pg_backup_custom.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/src/bin/pg_dump/pg_backup_custom.c b/src/bin/pg_dump/pg_backup_custom.c index e44b887eb29..b971e3bc16e 100644 --- a/src/bin/pg_dump/pg_backup_custom.c +++ b/src/bin/pg_dump/pg_backup_custom.c @@ -755,9 +755,11 @@ _CloseArchive(ArchiveHandle *AH) * If possible, re-write the TOC in order to update the data offset * information. This is not essential, as pg_restore can cope in most * cases without it; but it can make pg_restore significantly faster - * in some situations (especially parallel restore). + * in some situations (especially parallel restore). We can skip this + * step if we're not dumping any data. */ - if (ctx->hasSeek && + if (AH->public.dopt->dumpData && + ctx->hasSeek && fseeko(AH->FH, tpos, SEEK_SET) == 0) WriteToc(AH); } -- 2.39.5 (Apple Git-154)