Horton

Re: [HACKERS] Custom compression methods

Justin Pryzby <pryzby@telsasoft.com>

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From: Justin Pryzby <pryzby@telsasoft.com>
To: Robert Haas <robertmhaas@gmail.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>, pgsql-hackers@lists.postgresql.org
Date: 2021-02-09T20:37:37Z
Lists: pgsql-hackers 
I see the thread got broken somehow (or cfbot thought it did), so I added the
new thread, and this is now passing all tests.  (I think using the v22
patches).  http://cfbot.cputube.org/dilip-kumar.html

On Fri, Feb 05, 2021 at 11:07:53AM -0500, Robert Haas wrote:
> > 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...

I think you misunderstood: I mean that the WIP patch should default to
--enable-lz4, to exercise on a few CI.  It's hardly useful to run CI with the
feature disabled.  I assume that the patch would be committed with default
--disable-lz4.

On Fri, Feb 05, 2021 at 11:23:46AM -0500, Robert Haas wrote:
> On Fri, Feb 5, 2021 at 11:07 AM Robert Haas <robertmhaas@gmail.com> wrote:
> > 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.
> 
> Oh, I guess you're thinking about the case where someone wants to run
> the tests with a different default. That might be a good reason to
> have this. But then those changes should go in 0002.

Right, it's not one-time, it's also whenever setting a non-default compression
method.  I say it should go into 0001 to avoid a whole bunch of churn in
src/test/regress, and then more churn (and rebase conflicts in other patches)
while adding HIDE_COMPRESSAM in 0002.

-- 
Justin

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.