Re: Delete query takes exorbitant amount of time - Mailing list pgsql-performance

Simon Riggs <simon@2ndquadrant.com> writes:
> If action is NO ACTION or RESTRICT then
>     we need to SELECT at most 1 row that matches the criteria
>     which means we can use LIMIT 1

> If action is CASCADE, SET NULL, SET DEFAULT then
>     we need to UPDATE or DELETE all rows that match the criteria
>     which means we musnt use LIMIT and need to use FOR UPDATE

Huh?  UPDATE/DELETE don't use FOR UPDATE.  I think you have failed
to break down the cases sufficiently.  In particular it matters which
side of the RI constraint you are working from ...

            regards, tom lane