From: scott ribe <scott_ribe@elevated-dev.com>
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Subject: Re: Ideas to deal with table corruption
Date: Sat, 6 Jan 2018 12:14:56 -0700
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On Jan 6, 2018, at 12:11 PM, Corey Taylor <corey.taylor.fl@gmail.com> =
wrote:
> Is it possible for an index to not exist on those columns?
>=20
> =
https://www.postgresql.org/docs/current/static/ddl-constraints.html#DDL-CO=
NSTRAINTS-FK
>=20
> "A foreign key must reference columns that either are a primary key or =
form a unique constraint. This means that the referenced columns always =
have an index (the one underlying the primary key or unique constraint); =
so checks on whether a referencing row has a match will be efficient."

One should also remember that the foreign key itself should usually be =
indexed, lest a delete on the referenced table require a table scan on =
the referencing table.

--
Scott Ribe
https://www.linkedin.com/in/scottribe/
(303) 722-0567