Waiting for 9.2 – NULLS from pg_*_size() functions

On 19t of January, Heikki Linnakangas committed patch:

Make pg_relation_size() and friends return NULL if the object doesn't exist.
 
That avoids errors when the functions are used in queries like "SELECT
pg_relation_size(oid) FROM pg_class", and a table is dropped concurrently.
 
Phil Sorber

Continue reading Waiting for 9.2 – NULLS from pg_*_size() functions

Tips N’ Tricks – getting sizes of relations without locks

If you have production DB servers, chances are you're running variant of these queries:

SELECT SUM(pg_relation_size(oid)) FROM pg_class WHERE relkind = 'i'
SELECT SUM(pg_relation_size(oid)) FROM pg_class WHERE relkind = 'r'

To get summarized size of tables and/or indexes in your database (for example for graphing purposes).

This (getting pg_relation_size for rows in pg_class) has one problem – it can lock, or it can fail.

Continue reading Tips N' Tricks – getting sizes of relations without locks

Waiting for 9.0 – table and index sizes

On 19th of January Tom Lane committed really brilliant patch:

Log Message:
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Add pg_table_size() and pg_indexes_size() to provide more user-friendly
wrappers around the pg_relation_size() function.
 
Bernd Helmle, reviewed by Greg Smith

Continue reading Waiting for 9.0 – table and index sizes