Re: [PATCH] Compression dictionaries for JSONB

This patch came up at the developer meeting in Brussels yesterday.
https://wiki.postgresql.org/wiki/FOSDEM/PGDay_2023_Developer_Meeting#v16_Patch_Triage

First, as far as I can tell, there is a large overlap between this patch
and "Pluggable toaster" patch. The approaches are completely different,
but they seem to be trying to fix the same problem: the fact that the
default TOAST stuff isn't good enough for JSONB. I think before asking
developers of both patches to rebase over and over, we should take a
step back and decide which one we dislike the less, and how to fix that
one into a shape that we no longer dislike.

(Don't get me wrong. I'm all for having better JSONB compression.
However, for one thing, both patches require action from the user to set
up a compression mechanism by hand. Perhaps it would be even better if
the system determines that a JSONB column uses a different compression
implementation, without the user doing anything explicitly; or maybe we
want to give the user *some* agency for specific columns if they want,
but not force them into it for every single jsonb column.)

Now, I don't think either of these patches can get to a committable
shape in time for v16 -- even assuming we had an agreed design, which
AFAICS we don't. But I encourage people to continue discussion and try
to find consensus.

--
Álvaro Herrera 48°01'N 7°57'E — https://www.EnterpriseDB.com/
"Doing what he did amounts to sticking his fingers under the hood of the
implementation; if he gets his fingers burnt, it's his problem." (Tom Lane)