From 95d7187172f2ac6c08dc92f1043e1662b0dab4ac Mon Sep 17 00:00:00 2001 From: Thomas Munro Date: Fri, 7 Feb 2020 12:04:57 +1300 Subject: [PATCH 2/3] Use pg_pwrite() in rewriteheap.c. This removes an lseek() call. --- src/backend/access/heap/rewriteheap.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/src/backend/access/heap/rewriteheap.c b/src/backend/access/heap/rewriteheap.c index 5869922ff8..9c29bc0e0f 100644 --- a/src/backend/access/heap/rewriteheap.c +++ b/src/backend/access/heap/rewriteheap.c @@ -1156,13 +1156,6 @@ heap_xlog_logical_rewrite(XLogReaderState *r) path, (uint32) xlrec->offset))); pgstat_report_wait_end(); - /* now seek to the position we want to write our data to */ - if (lseek(fd, xlrec->offset, SEEK_SET) != xlrec->offset) - ereport(ERROR, - (errcode_for_file_access(), - errmsg("could not seek to end of file \"%s\": %m", - path))); - data = XLogRecGetData(r) + sizeof(*xlrec); len = xlrec->num_mappings * sizeof(LogicalRewriteMappingData); @@ -1170,7 +1163,7 @@ heap_xlog_logical_rewrite(XLogReaderState *r) /* write out tail end of mapping file (again) */ errno = 0; pgstat_report_wait_start(WAIT_EVENT_LOGICAL_REWRITE_MAPPING_WRITE); - if (write(fd, data, len) != len) + if (pg_pwrite(fd, data, len, xlrec->offset) != len) { /* if write didn't set errno, assume problem is no disk space */ if (errno == 0) -- 2.23.0