Re: refresh materialized view concurrently

On 17 June 2013 12:13, Heikki Linnakangas <hlinnakangas@vmware.com> wrote:
> On 14.06.2013 19:05, Kevin Grittner wrote:
>>
>> Attached is a patch for REFRESH MATERIALIZED VIEW CONCURRENTLY for
>> 9.4 CF1.  The goal of this patch is to allow a refresh without
>> interfering with concurrent reads, using transactional semantics.
>>
>> It is my hope to get this committed during this CF to allow me to
>> focus on incremental maintenance for the rest of the release cycle.
>
>
> I must say this seems a bit pointless on its own. But if it's a stepping
> stone to incremental maintenance, I have no objections.

There are generally 4 kinds of mat view

1. Transactionally updated
2. Incremental update, eventually consistent
3. Incremental update, regular refresh
4. Full refresh

At the moment we only have type 4 and it holds a full lock while it
runs. We definitely need a CONCURRENTLY option and this is it.

Implementing the other types won't invalidate what we currently have,
so this makes sense to me.

--Simon Riggs                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services