Re: Seeking performance advice and explanation for high I/O on 8.3

Robert Haas <robertmhaas(at)gmail(dot)com>:

> Do you by any chance have a bazillion databases in this cluster? Can
> you do these?

> select sum(1) from pg_database;

1555

> select pg_relation_size('pg_database');

221184

> select sum(pg_column_size(d.*)) from pg_database;

That gave me:

ERROR: missing FROM-clause entry for table "d"
LINE 1: select sum(pg_column_size(d.*)) from pg_database;

So I did this:

select sum(pg_column_size(d.*)) from pg_database as d;

and got:

192910

Also did this:

select sum(pg_database_size(datname)) from pg_database;

and got:

13329800428 (12.4GB)

Scott