Set up PostgreSQL for Monitoring

User Permissions

Create a non-superuser and grant monitoring permissions. To achieve this, perform the following steps to create a SECURITY DEFINER function. This allows non-superusers to view the contents of pg_stat_activity and pg_stat_statements.

Warning: You must be a superuser to execute this section.

Call the get_sa() function:

CREATE FUNCTION get_sa() 
RETURNS SETOF pg_stat_activity LANGUAGE sql AS
$$ SELECT * FROM pg_catalog.pg_stat_activity; $$
VOLATILE
SECURITY DEFINER;
 
CREATE VIEW pg_stat_activity_allusers AS SELECT * FROM get_sa(); 
GRANT SELECT ON pg_stat_activity_allusers TO public;

Call the get_querystats( ) function:

CREATE FUNCTION get_querystats() 
RETURNS SETOF pg_stat_statements LANGUAGE sql 	AS
$$ SELECT * FROM pg_stat_statements; $$
VOLATILE
SECURITY DEFINER;
CREATE VIEW pg_stat_statements_allusers AS SELECT * FROM get_querystats();
GRANT SELECT ON pg_stat_statements_allusers TO public;

The monitoring user must also be able to connect remotely to the PostgreSQL instance from Splunk AppDynamics for the database machine.

Enable the pg_stat_statements Section

Warning: You must be a superuser to execute this section.

Run the following command to create the pg_stat_statements extension:
```
create extension pg_stat_statements
```
Restart the database if you are creating the pg_stat_statements extension for the first time.

Validate the Setup

Warning: Ensure that the newly created appduser (monitoring user) executes this section.

Run the following queries:

SELECT * FROM pg_stat_activity_allusers

SELECT * FROM pg_stat_statements_allusers

If the queries run successfully and you get an output, the setup is successful.