Re: DB size growing exponentially when materialized view refreshed concurrently (postgres 9.6)

> On 25 Jun 2018, at 19:21, Vikas Sharma <shavikas(at)gmail(dot)com> wrote:
>
> I am looking for advice in a issue where two materialized views are being refreshed concurrently and dbsize has grown to 150gb from 4gb in two days.
>
> We use two materialized views to keep processed data for faster query results for a search function. Earlier materialized views were refreshed not concurrently and all was good on DB.
>
> We changed mv refresh to concurrently to take advantage of simultaneous access when mv refreshed. Now the refresh takes slightly longer and but DB size has grown exponentially.
>
> I ran full vacuum on DB and size again reduced to 4gb from 150gb.

You did not disable or tune down autovacuum perchance?
With materialized view refreshes that often, you probably need fairly aggressive autovacuuming on that table - you can tune autovacuum parameters per table (see Storage parameters). That probably won't put you at 4GB, more around double that size, but it should stay a reasonable size that way.

Regards,

Alban Hertroys
--
If you can't see the forest for the trees,
cut the trees and you'll find there is no forest.