Re: Config for fast huge cascaded updates

On Mon, Jun 26, 2017 at 07:26:08PM -0700, Joshua D. Drake wrote:

> Alternatively, and ONLY do this if you take a backup right before hand, you
> can set the table unlogged, make the changes and assuming success, make the
> table logged again. That will great increase the write speed and reduce wal
> segment churn.

Note that this is not for just that table, but for all of the
implicated ones because of the CASCADE statements. It sounds like the
OP is basically rewriting a significant chunk of the entire database,
so nothing is going to be super fast: all those CASCADEs have to fire
and all those other tables need to be updated too.

> However, if that fails, the table is dead. You will have to reload it from
> backup.

Right, and that goes for all the affected tables.

Best regards,

A

--
Andrew Sullivan
ajs(at)crankycanuck(dot)ca