Re: Table size does not include toast size

Cédric Villemain <cedric.villemain.debian@gmail.com>

From: Cédric Villemain <cedric.villemain.debian@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Greg Smith <greg@2ndquadrant.com>, Bernd Helmle <mailings@oopsware.de>, Rafael Martinez <r.m.guerrero@usit.uio.no>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2009-12-22T10:46:32Z
Lists: pgsql-hackers
2009/12/21 Tom Lane <tgl@sss.pgh.pa.us>:
> Greg Smith <greg@2ndquadrant.com> writes:
>> To answer Rafael's concerns directly:  you're right that this is
>> confusing.  pg_relation_size is always going to do what it does right
>> now just because of how that fits into the design of the database.
>> However, the documentation should be updated to warn against the issue
>> with TOAST here.  And it should be easier to get the total you're like
>> to see here:  main relation + toasted parts, since that's what most DBAs
>> want in this area.
>
> Perhaps invent  pg_table_size() = base table + toast table + toast index
> and             pg_indexes_size() = all other indexes for table
> giving us the property pg_table_size + pg_indexes_size =
> pg_total_relation_size

Did you mean :
 pg_table_size() = base table + toast table
 pg_indexes_size() = base indexes + toast indexes
?

>
> I think the 8.4 documentation already makes it apparent that
> pg_relation_size is a pretty low-level number.  If we invent other
> functions with obvious names, that should be sufficient.
>
>                        regards, tom lane
>
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