From: Ronan Dunklau <ronan.dunklau@aiven.io>
To: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers@lists.postgresql.org
Cc: Pgsql Hackers <pgsql-hackers@postgresql.org>,
 Paul Jungwirth <pj@illuminatedcomputing.com>
Subject: Re: Exclusion constraints on partitioned tables
Date: Tue, 24 Jan 2023 15:38:13 +0100
Message-ID: <10212835.nUPlyArG6x@aivenlaptop>
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Le vendredi 16 d=E9cembre 2022, 06:11:49 CET Paul Jungwirth a =E9crit :
> On 12/15/22 16:12, Tom Lane wrote:
> >> This patch also requires the matching constraint columns to use equali=
ty
> >> comparisons (`(foo WITH =3D)`), so it is really equivalent to the exis=
ting
> >> b-tree rule.
> >=20
> > That's not quite good enough: you'd better enforce that it's the same
> > equality operator (and same collation, if relevant) as is being used
> > in the partition key.
> > [snip]
> > It might work better to consider the operator itself and ask if
> > it's equality in the same btree opfamily that's used by the
> > partition key.
>=20
> Thank you for taking a look! Here is a comparison on just the operator
> itself.
>=20

I've taken a look at the patch, and I'm not sure why you keep the restricti=
on=20
on the Gist operator being of the RTEqualStrategyNumber strategy. I don't=20
think  we have any other place where we expect those strategy numbers to=20
match. For hash it's different, as the hash-equality is the only operator=20
strategy and as such there is no other way to look at it. Can't we just=20
enforce partition_operator =3D=3D exclusion_operator without adding the=20
RTEqualStrategyNumber for the opfamily into the mix ?