Re: Add LZ4 compression in pg_dump

Michael Paquier <michael@paquier.xyz>

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: 2022-12-03T02:45:30Z
Lists: pgsql-hackers
On Fri, Dec 02, 2022 at 04:15:10PM +0000, gkokolatos@pm.me wrote:
> You are very correct. However one can glob after the fact. Please find
> 0001 of the attached v14 which attempts to implement it.

+       if ($pgdump_runs{$run}->{glob_pattern})
+       {
+               my $glob_pattern = $pgdump_runs{$run}->{glob_pattern};
+               my @glob_output = glob($glob_pattern);
+               is(scalar(@glob_output) > 0, 1, "glob pattern matched")
+       }

While this is correct in checking that the contents are compressed
under --with-zlib, this also removes the coverage where we make sure
that this command is able to complete under --without-zlib without
compressing any of the table data files.  Hence my point from
upthread: this test had better not use compile_option, but change
glob_pattern depending on if the build uses zlib or not.

In order to check this behavior with defaults_custom_format, perhaps
we could just remove the -Z6 from it or add an extra command for its
default behavior?
--
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,