Horton

Re: Add LZ4 compression in pg_dump

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Justin Pryzby <pryzby@telsasoft.com>, Georgios <gkokolatos@protonmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Rachel Heaton <rachelmheaton@gmail.com>
Date: 2022-03-29T05:03:12Z
Lists: pgsql-hackers 
On Mon, Mar 28, 2022 at 08:36:15AM -0400, Robert Haas wrote:
> Well, I think the first thing we should do is get rid of enum
> WalCompressionMethod and use enum WalCompression instead. They've got
> the same elements and very similar names, but the WalCompressionMethod
> ones just have names like COMPRESSION_NONE, which is too generic,
> whereas WalCompressionMethod uses WAL_COMPRESSION_NONE, which is
> better. Then I think we should also rename the COMPR_ALG_* constants
> in pg_dump.h to names like DUMP_COMPRESSION_*. Once we do that we've
> got rid of all the unprefixed things that purport to be a list of
> compression algorithms.

Yes, having a centralized enum for the compression method would make
sense, along with the routines to parse and get the compression method
names.  At least that would be one step towards more unity in
src/common/.

> Then, if people are willing to adopt the syntax that the
> backup_compression.c/h stuff supports as a project standard (+1 from
> me) we can go the other way and rename that stuff to be more generic,
> taking backup out of the name.

I am not sure about the specification part which is only used by base
backups that has no client-server requirements, so option values would
still require their own grammar.
--
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,