Re: Pluggable toaster

Hi Nikita,

> Pluggable TOAST is provided as an interface to allow developers to plug
> in custom TOAST mechanics. It does not determines would it be universal
> Toaster or one data type, but syntax for universal Toaster is out of scope
> for this patchset.

If I understand correctly, what is going to happen - the same
interface TsrRoutine is going to be used for doing two things:

1) Implementing type-aware TOASTers as a special case for the default
TOAST algorithm when EXTERNAL storage strategy is used.
2) Implementing universal TOASTers from scratch that have nothing to
do with the default TOAST algorithm.

Assuming this is the case, using the same interface for doing two very
different things doesn't strike me as a great design decision. While
working on v24 you may want to rethink this.

Personally I believe that Pluggable TOASTers should support only case
#2. If there is a need of reusing parts of the default TOASTer,
corresponding pieces of code should be declared as non-static and
called from the pluggable TOASTers directly.

Alternatively we could have separate interfaces for case #1 and case
#2 but this IMO becomes rather complicated.

> I'm currently working on a revision of Pluggable TOAST that would make
> dropping Toaster possible if there is no data TOASTed with it, along with
> several other major changes. It will be available in this (I hope so) or the
> following, if I won't make it in time, commitfest.

Looking forward to v24!

This is a major change so I hope there will be more feedback from
other people on the mailing list.

--
Best regards,
Aleksander Alekseev