Horton

Re: [HACKERS] Custom compression methods

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Dilip Kumar <dilipbalaut@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 Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-02-05T16:07:53Z
Lists: pgsql-hackers 
On Fri, Feb 5, 2021 at 10:56 AM Justin Pryzby <pryzby@telsasoft.com> wrote:
> Could you comment on the patch I sent on Jan 30 ?  I think it would be squished
> into 0001.

I don't see why we have to do that. Seems fine to have it as a separate patch.

> Also, what about the idea to add HIDE_COMPRESSAM ?  Right now, your patch
> changes a great many regression tests, and I doubt many people are going to try
> to look closely to verify the differences, now, or when setting a non-default
> compression method.

Personally, my preference is to just update the test outputs. It's not
important whether many people look closely to verify the differences;
we just need to look them over on a one-time basis to see if they seem
OK. After that it's 0 effort, vs. having to maintain HIDE_COMPRESSAM
forever.

> Also, I think we may want to make enable-lz4 the default *for testing
> purposes*, now that the linux and BSD environments include that.

My guess was that would annoy some hackers whose build environments
got broken. If everyone thinks otherwise I'm willing to be persuaded,
but it's going to take more than 1 vote...

-- 
Robert Haas
EDB: http://www.enterprisedb.com

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.