Re: altering foreign key without a table scan

Vincent de Phily <vincent(dot)dephily(at)mobile-devices(dot)fr> writes:
> On Thursday 18 August 2011 13:08:18 Jerry Sievers wrote:
>> Your 2 catalog fields of interest are;
>> pg_constraint.(confupdtype|confdeltype)
>>
>> Changing those for the relevant FKs should satisfy your needs. I am
>> not aware of those field values being duplicated anywhere.

> Thanks for your answer. Experimenting a bit, those columns seem to have only a
> cosmetic impact, meaning that "\d" will show the schema you expect, but the
> behaviour remains unchanged (even after restarting postgres).

> Digging further however, I found that pg_triggers can be used for my means :

IIRC, there are fields of pg_constraint that are copied into the
pg_trigger rows for the supporting triggers, so as to save one catalog
lookup at run time. If you diddle one manually, you'd better diddle
both.

regards, tom lane