Horton

Re: Add LZ4 compression in pg_dump

Justin Pryzby <pryzby@telsasoft.com>

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From: Justin Pryzby <pryzby@telsasoft.com>
To: Georgios <gkokolatos@protonmail.com>
Cc: pgsql-hackers@lists.postgresql.org, Rachel Heaton <rachelmheaton@gmail.com>
Date: 2022-03-04T16:10:39Z
Lists: pgsql-hackers 
The patch is failing on cfbot/freebsd.
http://cfbot.cputube.org/georgios-kokolatos.html

Also, I wondered if you'd looked at the "high compression" interfaces in
lz4hc.h ?  Should pg_dump use that ?

On Fri, Feb 25, 2022 at 08:03:40AM -0600, Justin Pryzby wrote:
> Thanks for working on this.  Your 0001 looks similar to what I did for zstd 1-2
> years ago.
> https://commitfest.postgresql.org/32/2888/
> 
> I rebased and attached the latest patches I had in case they're useful to you.
> I'd like to see zstd included in pg_dump eventually, but it was too much work
> to shepherd the patches.  Now that seems reasonable for pg16.
> 
> With the other compression patches I've worked on, we've used an extra patch
> with changes the default to the new compression algorithm, to force cfbot to
> exercize the new code.
> 
> Do you know the process with commitfests and cfbot ?
> There's also this, which allows running the tests on cirrus before mailing the
> patch to the hackers list.
> ./src/tools/ci/README

Commits

  1. Advance input pointer when LZ4 compressing data

  2. Null-terminate the output buffer of LZ4Stream_gets

  3. Rework code defining default compression for dir/custom formats in pg_dump

  4. pg_dump: Use only LZ4 frame format for compression

  5. Minor comment improvements for compress_lz4

  6. Unify buffer sizes in pg_dump compression API

  7. Improve type handling in pg_dump's compress file API

  8. Improve wording in pg_dump compression docs

  9. Fix condition in pg_dump TAP test

  10. Add LZ4 compression to pg_dump

  11. Introduce a generic pg_dump compression API

  12. Prepare pg_dump internals for additional compression methods

  13. Fix behavior with pg_restore -l and compressed dumps

  14. Add 250c8ee07ed to git-blame-ignore-revs

  15. Provide test coverage in pg_dump for default behaviors with compression

  16. Switch pg_dump to use compression specifications

  17. Refactor code parsing compression option values (-Z/--compress)

  18. meson: Add some missing env settings for tests of pg_dump and pg_verifybackup

  19. Extend TAP tests of pg_dump to test for compression with gzip

  20. Clean up some dead code in pg_dump with tar format and gzip compression

  21. Add TAP test in pg_dump with --format=tar and --compress

  22. Replace BASE_BACKUP COMPRESSION_LEVEL option with COMPRESSION_DETAIL.

  23. Refactor the pg_dump zlib code from pg_backup_custom.c to a separate file,