Bug 579810

The table metrics cannot be collected when the tables do not belong to the public schema.
The problem appears on the following environment :
Monitored Database : Postgresql 8.3
RHQ agent plugin version : rhq-postgres-plugin-1.3.1
Jopr Server version : 2.3.1

To reproduce the problem, create a new schema in a monitored database :
create schema myschema;

Then create a table in the new schema :
create table myschema.mytable (name varchar(20));

In Jopr, no metrics are available for the table mytable.
The role used by the agent to connect to the Postgresql DB is postgres.

The reason for the failure to collect the metrics can be found in the Postgresql logs :

ERROR:  relation "mytable" does not exist
STATEMENT:  SELECT ts.*,  pg_relation_size(ts.relname) AS table_size, pg_total_relation_size(ts.relname) AS total_size,
          ios.heap_blks_read, ios.heap_blks_hit, ios.idx_blks_read, ios.idx_blks_hit,
          ios.toast_blks_read, ios.toast_blks_hit, ios.tidx_blks_read, ios.tidx_blks_hit
        FROM pg_stat_user_tables ts LEFT JOIN pg_statio_user_tables ios on ts.relid = ios.relid
        WHERE ts.relname = $1

This is due to the fact that by default the search_path of a postgresql role is :
"$user",public

By default, the newly created schema is not looked in when performing a query.

To fix the problem, the select statement could me modified to look like this :

SELECT ts.*,
          pg_relation_size(ts.schemaname || '.' || ts.relname) AS table_size,
          pg_total_relation_size(ts.schemaname || '.' || ts.relname) AS total_size,
          ios.heap_blks_read, ios.heap_blks_hit, ios.idx_blks_read, ios.idx_blks_hit,
          ios.toast_blks_read, ios.toast_blks_hit, ios.tidx_blks_read, ios.tidx_blks_hit
        FROM pg_stat_user_tables ts LEFT JOIN pg_statio_user_tables ios on ts.relid = ios.relid
        WHERE ts.relname = 'mytable' and ts.schemaname='myschema';

As a temporary workaround, one could alter the search_path for the role postgres :

alter role postgres set search_path="$user",public,myschema;