0

I am migrating oracle database to postgresql.

While migration came to know with the following query in the oracle side.

Oracle Query:

SELECT
TRIM(value) AS val
FROM v$parameter
WHERE name = 'job_queue_processes';

I just want to know how can we get the maximum number of job slaves per instance that can be created for the execution at the postgresql side.

I have created pg_cron extension and created required jobs till now. But one of the function is using above query in oracle, so I just want to convert it into the postgresql.

MAK
  • 6,824
  • 25
  • 74
  • 131

1 Answers1

1

The documentation is usually a good source of information.

Important: By default, pg_cron uses libpq to open a new connection to the local database.

In this case, there is no specific limit. It would be limited in the same way other user connections are limited. Mostly by max_connections, but possibly lowered from that for particular users or particular databases by the ALTER command. You could create a user specifically for cron if you wanted to limit its connections separately, then grant that user privileges of other roles it will operate on behalf of. I don't know what pg_cron does if the limit is reached, does it deal with it gracefully or not?

Alternatively, pg_cron can be configured to use background workers. In that case, the number of concurrent jobs is limited by the max_worker_processes setting, so you may need to raise that.

Note that the max number of workers may have to be shared with parallel execution workers and maybe with other extensions.

jjanes
  • 37,812
  • 5
  • 27
  • 34