Set A Statement Timeout Threshold For A Session

The statement_timeout variable is used to tell the PostgreSQL server that you want it to terminate statements (queries and transactions) that run past the specified threshold. This is a great way to prevent runaway queries in a production environment.

You can set this threshold with a set statement. It can take an integer argument of milliseconds. Here I set it to a timeout of 1 minute.

> set statement_timeout = 60000;
SET
> show statement_timeout;
 statement_timeout
-------------------
 1min
(1 row)

This will set the statement_timeout for the duration of the session. It won't effect other sessions.

You can also set the threshold with a string argument which allows you to include a unit of time. Here I set it to 30 seconds.

> set statement_timeout = '30s';
SET
> show statement_timeout;
 statement_timeout
-------------------
 30s
(1 row)

Now that the statement_timeout is set to 30s, I can run a query that I know will exceed that threshold (pg_sleep).

> select pg_sleep(31);
ERROR:  canceling statement due to statement timeout
Time: 30001.997 ms (00:30.002)

After 30 seconds have passed, the Postgres server will interrupt the query.