Horton

Re: [HACKERS] Custom compression methods

x4mmm@yandex-team.ru

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From: Andrey Borodin <x4mmm@yandex-team.ru>
To: Dilip Kumar <dilipbalaut@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Tomas Vondra <tomas.vondra@2ndquadrant.com>, Alexander Korotkov <a.korotkov@postgrespro.ru>, David Steele <david@pgmasters.net>, Ildus Kurbangaliev <i.kurbangaliev@gmail.com>, Dmitry Dolgov <9erthalion6@gmail.com>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2020-12-28T06:14:43Z
Lists: pgsql-hackers 

> 28 дек. 2020 г., в 10:20, Dilip Kumar <dilipbalaut@gmail.com> написал(а):
> 
> On Sun, Dec 27, 2020 at 12:40 PM Andrey Borodin <x4mmm@yandex-team.ru> wrote:
>> 
>> 
>> 
>>> 25 дек. 2020 г., в 14:34, Dilip Kumar <dilipbalaut@gmail.com> написал(а):
>>> 
>>> <v16-0002-alter-table-set-compression.patch> <v16-0004-Create-custom-compression-methods.patch> <v16-0005-new-compression-method-extension-for-zlib.patch> <v16-0001-Built-in-compression-method.patch> <v16-0003-Add-support-for-PRESERVE.patch> <v16-0006-Support-compression-methods-options.patch>
>> 
>> Maybe add Lz4\Zlib WAL FPI compression on top of this patchset? I'm not insisting on anything, it just would be so cool to have it...
>> 
>> BTW currently there are Oid collisions in original patchset.
> 
> Thanks for the patch.  Maybe we can allow setting custom compression
> methods for wal compression as well.

No, unfortunately, we can't use truly custom methods. Custom compression handlers are WAL-logged. So we can use only static set of hardcoded compression methods.

Thanks!

Best regards, Andrey Borodin.

Commits

  1. docs: Update TOAST storage docs for configurable compression.

  2. Further tweaking of pg_dump's handling of default_toast_compression.

  3. Fix interaction of TOAST compression with expression indexes.

  4. Tidy up more loose ends related to configurable TOAST compression.

  5. Short-circuit slice requests that are for more than the object's size.

  6. Mostly-cosmetic adjustments of TOAST-related macros.

  7. Remove useless configure probe for <lz4/lz4.h>.

  8. Error on invalid TOAST compression in CREATE or ALTER TABLE.

  9. docs: Fix omissions related to configurable TOAST compression.

  10. More code cleanup for configurable TOAST compression.

  11. Bring configure support for LZ4 up to snuff.

  12. Make compression.sql regression test independent of default.

  13. Use valid compression method in brin_form_tuple

  14. Fix up pg_dump's handling of per-attribute compression options.

  15. Allow configurable LZ4 TOAST compression.

  16. Fix inconsistencies in the code

  17. Mostly-cosmetic improvements in memory chunk header alignment coding.

  18. Allow numeric to use a more compact, 2-byte header in many cases.