Re: [PATCH] Compression dictionaries for JSONB

Hi Matthias,

> These are just my initial thoughts I would like to share though. I may
> change my mind after diving deeper into a "pluggable TOASTer" patch.

I familiarized myself with the "pluggable TOASTer" thread and joined
the discussion [1].

I'm afraid so far I failed to understand your suggestion to base
"compression dictionaries" patch on "pluggable TOASTer", considering
the fair amount of push-back it got from the community, not to mention
a somewhat raw state of the patchset. It's true that Teodor and I are
trying to address similar problems. This however doesn't mean that
there should be a dependency between these patches.

Also, I completely agree with Tomas [2]:

> My main point is that we should not be making too many radical
> changes at once - it makes it much harder to actually get anything done.

IMO the patches don't depend on each other but rather complement each
other. The user can switch between different TOAST methods, and the
compression dictionaries can work on top of different TOAST methods.
Although there is also a high-level idea (according to the
presentations) to share common data between different TOASTed values,
similarly to what compression dictionaries do, by looking at the
current feedback and considering the overall complexity and the amount
of open questions (e.g. interaction with different TableAMs, etc), I
seriously doubt that this particular part of "pluggable TOASTer" will
end-up in the core.

[1]: https://postgr.es/m/CAJ7c6TOMPiRs-CZ%3DA9hyzxOyqHhKXxLD8qCF5%2BGJuLjQBzOX4A%40mail.gmail.com
[2]: https://postgr.es/m/9ef14537-b33b-c63a-9938-e2b413db0a4c%40enterprisedb.com

--
Best regards,
Aleksander Alekseev