Re: ATTACH PARTITION cost grows linearly with pg_constraint size (seqscan in CloneFkReferenced), much worse since not-null constraints are in pg_constraint (PG 18)

On 2026-Sep-29, Manu wrote:

> I'd be glad to put a patch together once there's a sense of the
> preferred direction. The partial index is the smallest change, but
> whether a new catalog index is the way to go, versus the pg_depend
> lookup or the trigger-based early exit, is more your and the
> committers' call. Happy to test any of them against the reproducer.

I vaguely recall looking into adding such an index, and finding out that
we don't support partial indexes on catalogs. Is that doable in some
clean way nowadays? (Or maybe the index worked fine, and what failed
was adding a syscache on top of it? Not sure.)

I first mentioned this in 2019 ...
https://postgr.es/m/20190318220223.GA15196@alvherre.pgsql

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