Horton

Re: [PATCH v1] parallel pg_restore: avoid disk seeks when jumping short distance forward

Nathan Bossart <nathandbossart@gmail.com>

View thread View on postgr.es
From: Nathan Bossart <nathandbossart@gmail.com>
To: Dimitrios Apostolou <jimis@gmx.net>
Cc: pgsql-hackers@lists.postgresql.org, Tom Lane <tgl@sss.pgh.pa.us>
Date: 2025-04-01T20:04:00Z
Lists: pgsql-hackers 
On Tue, Apr 01, 2025 at 09:33:32PM +0200, Dimitrios Apostolou wrote:
> It didn't break any test, but I also don't see any difference, the
> performance boost is noticeable only when restoring a huge archive that is
> missing offsets.

This seems generally reasonable to me, but how did you decide on 1MB as the
threshold?  Have you tested other values?  Could the best threshold vary
based on the workload and hardware?

-- 
nathan

Commits

  1. Avoid short seeks in pg_restore.

  2. Don't rely on zlib's gzgetc() macro.

  3. Add more TAP test coverage for pg_dump.

  4. Split 002_pg_dump.pl into two test files.

  5. Align the data block sizes of pg_dump's various compression modes.

  6. Fix serious performance problems in LZ4Stream_read_internal.

  7. Fix poor buffering logic in pg_dump's lz4 and zstd compression code.

  8. Fix issue with reading zero bytes in Gzip_read.

  9. Restore test coverage of LZ4Stream_gets().