Thread: WAL replay does not verify integrity

As demonstrated here:
http://archives.postgresql.org/pgsql-general/2010-02/msg01057.php

it can happen that you end up with a corrupt database
if you use PITR to recover past a hardware failure.

It seems that unique constraints are not verified during
WAL replay.

Is that intentional or an oversight that should be fixed?

Yours,
Laurenz Albe

Albe Laurenz wrote:
> As demonstrated here:
> http://archives.postgresql.org/pgsql-general/2010-02/msg01057.php
> 
> it can happen that you end up with a corrupt database
> if you use PITR to recover past a hardware failure.
> 
> It seems that unique constraints are not verified during
> WAL replay.
> 
> Is that intentional or an oversight that should be fixed?

It's intentional. WAL replay works at a lower level, it has no knowledge
of operators or the concept of uniqueness.

--  Heikki Linnakangas EnterpriseDB   http://www.enterprisedb.com