On Tue, Mar 10, 2026 at 5:23 PM Matthias van de Meent
<boekewurm+postgres@gmail.com> wrote:
>
> They're exclusively for btree code's use; extensions (*) must not add
> to (or change the meaning of) those bits, lest they create a forward
> incompatibility with core PostgreSQL btree code in newer major
> versions; it would cause corrupted binary upgraded databases.
> But patches against core btree code can use those bits, because
> forward compatibility is less of an issue there - we don't really
> support binary upgrades manually patched systems, especially if they
> have incompatible on-disk data.
Noted, I'm looking at it from the core btree code side of things.
I'm unable to see a way where scans or VACUUM calls can recognise
transient merge states if we implement merging as an extension.
Madhav
