Horton

Re: [HACKERS] Custom compression methods

Justin Pryzby <pryzby@telsasoft.com>

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From: Justin Pryzby <pryzby@telsasoft.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Dilip Kumar <dilipbalaut@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Andres Freund <andres@anarazel.de>, 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: 2021-03-20T18:52:10Z
Lists: pgsql-hackers 
On Sat, Mar 20, 2021 at 01:36:15PM -0400, Tom Lane wrote:
> Justin Pryzby <pryzby@telsasoft.com> writes:
> > On Sat, Mar 20, 2021 at 04:37:53PM +0530, Dilip Kumar wrote:
> >> - And, 0008 and 0009, I think my
> >> 0001-Fixup-dump-toast-compression-method.patch[1] is doing this in a
> >> much simpler way, please have a look and let me know if you think that
> >> has any problems and we need to do the way you are doing here?
> 
> > I tested and saw that your patch doesn't output "SET default_toast_compression"
> > in non-text dumps (pg_dump -Fc).
> 
> Yeah, _doSetFixedOutputState is the wrong place: that runs on the
> pg_restore side of the fence, and would not have access to the
> necessary info in a separated dump/restore run.
> 
> It might be necessary to explicitly pass the state through in a TOC item,
> as we do for things like the standard_conforming_strings setting.

My patches do this in 0008 and 0009 - I'd appreciate if you'd take a look.
0009 edits parts of 0008, and if that's all correct then they should be
squished together.

https://www.postgresql.org/message-id/20210320074420.GR11765%40telsasoft.com

-- 
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.