diff options
| -rw-r--r-- | src/bin/pg_dump/pg_backup_custom.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/src/bin/pg_dump/pg_backup_custom.c b/src/bin/pg_dump/pg_backup_custom.c index f7c3af56304..2226520dffc 100644 --- a/src/bin/pg_dump/pg_backup_custom.c +++ b/src/bin/pg_dump/pg_backup_custom.c @@ -624,12 +624,19 @@ _skipData(ArchiveHandle *AH) lclContext *ctx = (lclContext *) AH->formatData; size_t blkLen; char *buf = NULL; - int buflen = 0; + size_t buflen = 0; blkLen = ReadInt(AH); while (blkLen != 0) { - if (ctx->hasSeek) + /* + * Seeks of less than stdio's buffer size are less efficient than just + * reading the data, at least on common platforms. We don't know the + * buffer size for sure, but 4kB is the usual value. (While pg_dump + * currently tries to avoid producing such short data blocks, older + * dump files often contain them.) + */ + if (ctx->hasSeek && blkLen >= 4 * 1024) { if (fseeko(AH->FH, blkLen, SEEK_CUR) != 0) pg_fatal("error during file seek: %m"); @@ -639,8 +646,8 @@ _skipData(ArchiveHandle *AH) if (blkLen > buflen) { free(buf); - buf = (char *) pg_malloc(blkLen); - buflen = blkLen; + buflen = Max(blkLen, 4 * 1024); + buf = (char *) pg_malloc(buflen); } if (fread(buf, 1, blkLen, AH->FH) != blkLen) { |