Horton

Re: Add LZ4 compression in pg_dump

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: gkokolatos@pm.me
Cc: Justin Pryzby <pryzby@telsasoft.com>, pgsql-hackers@lists.postgresql.org, Rachel Heaton <rachelmheaton@gmail.com>
Date: 2022-12-06T00:22:57Z
Lists: pgsql-hackers 
On Mon, Dec 05, 2022 at 12:48:28PM +0000, gkokolatos@pm.me wrote:
> I also took the liberty of applying the test pattern when it the dump
> is explicitly compressed.

Sticking with glob_patterns is fine by me.

> I was thinking a bit more about this. I think that we can use the list
> TOC option of pg_restore. This option will first print out the header
> info which contains the compression. Perl utils already support to 
> parse the generated output of a command. Please find an attempt to do
> so in the attached. The benefits of having some testing for this case
> become a bit more obvious in 0004 of the patchset, when lz4 is
> introduced.

This is where the fun is.  What you are doing here is more complete,
and we would make sure that the custom and data directory would always
see their contents compressed by default.  And it would have caught
the bug you mentioned upthread for the custom format.

I have kept things as you proposed at the end, added a few comments,
documented the new command_like and an extra command_like for
defaults_dir_format.  Glad to see this addressed, thanks!
--
Michael

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,