Re: pg_class (system) table increasing size.

On 11/16/2016 07:08 PM, dhaval jaiswal wrote:
>
>>> Because you are creating (specific) objects.
>
> I have gone through the link and  how would i figure out which
> specific object is causing this.  Can you please elaborate more here.

It is not any one object, it is the total of the objects(relations) as
defined here:

https://www.postgresql.org/docs/9.4/static/catalog-pg-class.html

48.11. pg_class

relkind     char           r = ordinary table, i = index, S = sequence, v = view,
m = materialized view, c = composite type, t = TOAST table, f = foreign
table

So if you do something like:

select relkind, relname from pg_class order by relkind, relname;

you should see what the entries are the table by their type. Might give
you a clue as to what is causing the growth.

>
>
> We do not have the much temporary table usage.
>
>
> Since the size is bigger (5 GB) to maintain. does it requires

The size you are referring to is the database size, the table size or
something else?


> maintenance as well for thepg_class.
>
>
> It seems its affecting performance.
>
>
> ------------------------------------------------------------------------
> *From:* David G. Johnston <david.g.johnston@gmail.com>
> *Sent:* Thursday, November 17, 2016 8:13 AM
> *To:* dhaval jaiswal
> *Cc:* pgsql-general@postgresql.org
> *Subject:* Re: [GENERAL] pg_class (system) table increasing size.
>
> On Wed, Nov 16, 2016 at 7:30 PM, dhaval jaiswal <dhavallj@hotmail.com
> <mailto:dhavallj@hotmail.com>>wrote:
>
>     PostgreSQL 9.4.0
>
> Are generalizing here or are you really running 2+ year old patch version?
>
>     Why pg_class table is getting bigger in size.
>
> Because you are creating (specific) objects.
>
> See: https://www.postgresql.org/docs/9.6/static/catalog-pg-class.html
>
>     How to stop increasing it.
>
> Stop creating (those specific) objects.
>
>     Does it affect the performance.
>
> It can - depends greatly on scale.
>
> Note, frequent usage of temporary tables is a common cause for this kind
> of behavior.
>
> David J.
>


--
Adrian Klaver
adrian.klaver@aklaver.com