Horton

Re: Add LZ4 compression in pg_dump

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, gkokolatos@pm.me, Andrew Dunstan <andrew@dunslane.net>, Alexander Lakhin <exclusion@gmail.com>, Justin Pryzby <pryzby@telsasoft.com>, shiy.fnst@fujitsu.com, pgsql-hackers@lists.postgresql.org, Rachel Heaton <rachelmheaton@gmail.com>
Date: 2023-05-08T22:10:55Z
Lists: pgsql-hackers 
On Mon, May 08, 2023 at 08:00:39PM +0200, Tomas Vondra wrote:
> The LZ4Stream_write() forgot to move the pointer to the next chunk, so
> it was happily decompressing the initial chunk over and over. A bit
> embarrassing oversight :-(
> 
> The custom format calls WriteDataToArchiveLZ4(), which was correct.
> 
> The attached patch fixes this for me.

Ouch.  So this was corrupting the dumps and the compression when
trying to write more than two chunks at once, not the decompression
steps.  That addresses the issue here as well, 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,