Re: New Event Trigger: table_rewrite

Simon Riggs <simon@2ndQuadrant.com> writes:
> It would be more useful to work on the applications of this....
>
> 1. INSERT into a table
> * Action start time
> * Schema
> * Tablename
> * Number of blocks in table
> which would then allow you to do these things run an assessment report
> showing which tables would be rewritten.

That should be done by the user, from within his Event Trigger code. For
that to be possible, the previous patch was missing a way to expose the
OID of the table being rewritten, I've now added support for that.

> 2. Get access to number of blocks, so you could limit rewrites only to
> smaller tables by putting a block limit in place.

Also, I did expand the docs to fully cover your practical use case of a
table_rewrite Event Trigger implementing such a table rewrite policy.

> 3. It might be even cooler to contemplate having pg_stat_activity
> publish an estimated end time.
> We'd probably need some kind of time_per_block parameter for each
> tablespace so we can estimate the time.

That feels like another patch entirely.

Regards,
--
Dimitri Fontaine                                        06 63 07 10 78
http://2ndQuadrant.fr     PostgreSQL : Expertise, Formation et Support