Re: Refactor code around GUC default_toast_compression

On Mon, Sep 14, 2026 at 04:48:26PM +0300, Aidar Imamov wrote:
> I rebased this onto current master (a23ab4862cf). It doesn't apply
> cleanly anymore — amcheck picked up the Oid8 TOAST-value-ID rework
> (toast_pointer_valueid / OID8_FORMAT) on top of the
> VARATT_EXTERNAL_IS_COMPRESSED -> VARATT_EXTERNAL_OID_IS_COMPRESSED
> rename. Both were easy to sort out, and the rebased patch is attached.

Yep, my fault for breaking my own patch. Thanks for looking at it.

> I also wondered about going further and moving the compress/decompress
> dispatch into the registry (function pointers + a cmid->name lookup).
> Probably out of scope for this patch, though — the registry centralizes
> the properties, and the dispatch part overlaps with the vartag
> direction you mention. Just flagging it in case it's worth a follow-up
> at some point.

Yeah, I am not sure at this point. What I am pretty sure about is
that this patch may not be the best path forward, actually. I was
playing with a few more things related to the extensiblity of the
compression methods in varlenas and this patch was not feeling like
optimal all the time.

Withdrawn for now.
--
Michael