Horton

Re: Add LZ4 compression in pg_dump

Tomas Vondra <tomas.vondra@enterprisedb.com>

View thread View on postgr.es
From: Tomas Vondra <tomas.vondra@enterprisedb.com>
To: Michael Paquier <michael@paquier.xyz>
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: 2023-05-09T12:54:31Z
Lists: pgsql-hackers 
On 5/9/23 00:10, Michael Paquier wrote:
> 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!

Yeah. Thanks for the report, should have been found during review.


regards

-- 
Tomas Vondra
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

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,