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commit    e3cc039a7d930ffe86e706944a2b3368bd3ef506
Author:   Nathan Bossart <nathan@postgresql.org>
Date:     Fri Apr 04 19:51:08 2025 +0000
First released in: 18.0

    Skip second WriteToc() call for custom-format dumps without data.
    
    Presently, "pg_dump --format=custom" calls WriteToc() twice.  The
    second call updates the data offset information, which allegedly
    makes parallel pg_restore significantly faster.  However, if we're
    not dumping any data, there are no data offsets to update, so we
    can skip this step.
    
    Reviewed-by: Jeff Davis <pgsql@j-davis.com>
    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..f7c3af56304 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; there are no offsets to update
+		 * in that case.
 		 */
-		if (ctx->hasSeek &&
+		if (ctx->hasSeek && AH->public.dopt->dumpData &&
 			fseeko(AH->FH, tpos, SEEK_SET) == 0)
 			WriteToc(AH);
 	}


[parent: d9c7911e1a5f]