Re: Disable unique constraint in Postgres

On 11/27/22 15:56, Mladen Gogala wrote:
> On 11/27/22 16:23, Ron wrote:
>>
>> Being an "enterprise dba", IMNSHO "disable constraint" (and more
>> specifically "*disable index*") is a /great/ feature for maintaining
>> tables.  For example, if you need to purge a *lot* of records into a
>> table, disable all indices except the index supporting your WHERE CLAUSE,
>> delete the data, and then re-enable the indices.  Bonus points if the
>> REENABLE commands can be done in parallel.
>>
>> Sure, you /can/ dig around for all of the CREATE INDEX statements, but
>> that leads to possible errors: "oops, forgot to recreate one of them", or
>> "typo caused one to fail".  OTOH, DISABLE INDEX and REENABLE INDEX are
>> idiot-proof, and can be automated.
>>
>> --
>> Angular momentum makes the world go 'round.
>
>
> You are aware that in Oracle "ALTER TABLE ENABLE CONSTRAINT" rebuilds the
> index used to enforce the constraint? You will not save any time by
> disabling and re-enabling constraints.
>

Eliminating mistakes and reducing DBA work are the point of DISABLE and
ENABLE INDEX, not saving clock time during the maintenance window.

--
Angular momentum makes the world go 'round.