Re: [GENERAL] Disk space usage analyzer?

2011-03-28 Thread Nicholson, Brad (Toronto, ON, CA)
> -Original Message-
> From: pgsql-general-ow...@postgresql.org [mailto:pgsql-general-
> ow...@postgresql.org] On Behalf Of Steve Crawford
> Sent: Monday, March 28, 2011 12:22 PM
> To: Yang Zhang
> Cc: pgsql-general@postgresql.org
> Subject: Re: [GENERAL] Disk space usage analyzer?
> 
> On 03/25/2011 07:58 PM, Yang Zhang wrote:
> > Is there any tool for breaking down how much disk space is used by
> > (could be freed by removing) various tables, indexes, selected rows,
> > etc.?  Thanks!
> >
> 
> You can use the pg_class table and the pg_relation_size (and optionally
> the pg_size_pretty) functions to get that info. This query gives table
> sizes and percent of overall usage.
> 
> BUT! It is only looking at tables, not indexes. If you want to know how
> much space will be freed by dropping a table, you will have to modify
> this query to total up the index space used for all the indexes
> associated with each table.

pg_total_relation_size() will give you the size of the table and the indexes on 
it.

Brad.



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Re: [GENERAL] Disk space usage analyzer?

2011-03-28 Thread Steve Crawford

On 03/25/2011 07:58 PM, Yang Zhang wrote:

Is there any tool for breaking down how much disk space is used by
(could be freed by removing) various tables, indexes, selected rows,
etc.?  Thanks!



You can use the pg_class table and the pg_relation_size (and optionally 
the pg_size_pretty) functions to get that info. This query gives table 
sizes and percent of overall usage.


BUT! It is only looking at tables, not indexes. If you want to know how 
much space will be freed by dropping a table, you will have to modify 
this query to total up the index space used for all the indexes 
associated with each table.


select
relname as table,
lpad(pg_size_pretty(pg_relation_size(oid)), 9) as size,
(100*pg_relation_size(oid)/(select sum(pg_relation_size(oid)) from 
pg_class where relkind='r'))::numeric(4,1) as percent

from
pg_class
where
relkind = 'r'
order by
relpages desc
;

  table   |   size| percent
--+---+-
 foobar   |   2310 MB |19.7
 foobaz   |   2021 MB |17.2
 bazbar   |   1642 MB |14.0
...

Cheers,
Steve



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[GENERAL] Disk space usage analyzer?

2011-03-25 Thread Yang Zhang
Is there any tool for breaking down how much disk space is used by
(could be freed by removing) various tables, indexes, selected rows,
etc.?  Thanks!

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