Re: Populating missing dates in postgresql data

David G. Johnston <david.g.johnston@gmail.com>

From: "David G. Johnston" <david.g.johnston@gmail.com>
To: Mitu Verma <mitu.verma@ericsson.com>
Cc: "pgsql-general@postgresql.org" <pgsql-general@postgresql.org>
Date: 2015-03-26T04:27:25Z
Lists: pgsql-general
On Wed, Mar 25, 2015 at 8:57 PM, Mitu Verma <mitu.verma@ericsson.com> wrote:

>  Hi,
>
>
>
> We have a customer complaining about the time taken by one of the
> application scripts while deleting older data from the log tables.
>
> During the deletion, customer reported that he often sees the below error
> and because of which table size doesn’t reduce.
>

​You should look into partitioning (implemented via inheritance) for your
log table so that you can simply issue a "DROP TABLE ..."​


>
> ERROR: canceling autovacuum task
>
> Date: 2015-03-14 04:29:19
>
> Context: automatic analyze of table
> "fm_db_Server3.mmsuper.audittraillogentry"
>
>
>
> We have the following queries in this regard:
>
> -          How often is the autovacuum task invoked by postgres
>
​As often as it needs to - based upon changes being made to tables​

>  -          If the task gets cancelled (while we were deleting data from
> the database) would this task be re-invoked at a later time?
>
​Yes​

>  -          If insertion of data into a table also impact this task?
>
​Yes​


>  -          If we can manually schedule this task to a particular time
> (like off peak hours)?
>

​Yes.  You can issue "ANALYZE" (or VACUUM) manually via SQL or the
PostgreSQL provided "vacuumdb" command using whatever external scheduling
mechanism you have at your disposal.

David J.