Re: pg_relation_size performance issue

Sorry, I left out

AND relkind = 'r'

will which restrict to just tables.

On Thu, Jun 4, 2015 at 10:24 AM, Hans Guijt <hg(at)terma(dot)com> wrote:

> Thanks, this is most helpful. I originally found that query somewhere on
> the internet and used it as-is.
>
>
>
> If I drop the restriction on table name I get a list that also includes
> indexes, constraints, etc. Is there a way to restrict the returned set to
> tables only?
>
>
>
>
>
> Hans Guijt
>
>
>
>
>
>
> *From:* Melvin Davidson [mailto:melvin6925(at)gmail(dot)com]
> *Sent:* 04 June 2015 16:08
> *To:* Tom Lane
> *Cc:* Hans Guijt; pgsql-general(at)postgresql(dot)org
> *Subject:* Re: [GENERAL] pg_relation_size performance issue
>
>
>
> Dammit pg_total_relation_size includes toast data. Thumb problems and to
> quick to hit send. :(
>
>
>
> On Thu, Jun 4, 2015 at 10:07 AM, Melvin Davidson <melvin6925(at)gmail(dot)com>
> wrote:
>
> Correction, pg_relation_size includes toast data.
>
>
>
> On Thu, Jun 4, 2015 at 10:03 AM, Melvin Davidson <melvin6925(at)gmail(dot)com>
> wrote:
>
> I'm not sure why you are adding toast to table size, since
> pg_relation_size already does that.
>
> http://www.postgresql.org/docs/9.3/interactive/functions-admin.html
>
> This query might work better and faster for you.
>
> SELECT n.nspname as schema,
> c.relname as table,
> a.rolname as owner,
> c.relfilenode as filename,
> c.reltuples::integer,
> pg_size_pretty(pg_relation_size( quote_ident( n.nspname ) ||
> '.' || quote_ident( c.relname ) )) as size,
> pg_size_pretty(pg_total_relation_size( quote_ident( n.nspname
> ) || '.' || quote_ident( c.relname ) )) as total_size,
> pg_relation_size( quote_ident( n.nspname ) || '.' ||
> quote_ident( c.relname ) ) as size_bytes,
> pg_total_relation_size( quote_ident( n.nspname ) || '.' ||
> quote_ident( c.relname ) ) as total_size_bytes,
> CASE WHEN c.reltablespace = 0
> THEN 'pg_default'
> ELSE (SELECT t.spcname
> FROM pg_tablespace t WHERE (t.oid =
> c.reltablespace) )
> END as tablespace
> FROM pg_class c
> JOIN pg_namespace n ON (n.oid = c.relnamespace)
> JOIN pg_authid a ON ( a.oid = c.relowner )
> WHERE c.relname = 'sensor'
> AND n.nspname = 'devtest';
>
>
>
> On Thu, Jun 4, 2015 at 9:50 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> Hans Guijt <hg(at)terma(dot)com> writes:
> > I have a Postgres 9.3.7 database, freshly created on Ubuntu 14 LTS 64
> bit, and at this time almost completely empty. I'm attempting to find the
> size of a table, using the following code:
> > SELECT
> > pg_relation_size (stat.relid),
> > CASE WHEN cl.reltoastrelid = 0 THEN
> > 0
> > ELSE
> > pg_relation_size (cl.reltoastrelid) + COALESCE ((
> > SELECT SUM (pg_relation_size (indexrelid)) FROM pg_index WHERE
> indrelid=cl.reltoastrelid
> > ), 0)::int8
> > END,
> > COALESCE ((SELECT SUM (pg_relation_size (indexrelid)) FROM pg_index
> WHERE indrelid=stat.relid), 0)::int8
> > FROM pg_stat_all_tables stat
> > JOIN pg_class cl ON cl.oid=stat.relid
> > JOIN pg_namespace ns ON cl.relnamespace=ns.oid
> > WHERE UPPER (cl.relname) = UPPER ('sensor')
> > AND UPPER (ns.nspname) = UPPER ('devtest')
>
> Getting rid of the useless join to pg_stat_all_tables would probably help;
> there's a lot of computation in that view.
>
> regards, tom lane
>
>
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>
>
> --
>
> *Melvin Davidson*
>
> *I reserve the right to fantasize. Whether or not you *
> * wish to share my fantasy is entirely up to you. [image: Image removed by
> sender.]*
>
>
>
>
> --
>
> *Melvin Davidson*
>
> *I reserve the right to fantasize. Whether or not you wish to share my
> fantasy is entirely up to you. [image: Image removed by sender.]*
>
>
>
>
> --
>
> *Melvin Davidson*
>
> *I reserve the right to fantasize. Whether or not you wish to share my
> fantasy is entirely up to you. [image: Image removed by sender.]*
>

--
*Melvin Davidson*
I reserve the right to fantasize. Whether or not you
wish to share my fantasy is entirely up to you.