`pg_cron launcher crashes with 'duplicate key value violates unique constraint'`

Last edited: 2/5/2026

The pg_cron launcher process crashes approximately every minute, displaying the error 'duplicate key value violates unique constraint "job_run_details_pkey"'.

Why does this happen?#

This issue occurs when the cron.runid_seq sequence is out of sync with the cron.job_run_details table. The sequence attempts to generate runid values that already exist in the table, leading to a unique key violation. This is typically due to the sequence's last value not being correctly aligned with the maximum runid already present in the table.

How to resolve this#

To resolve this, you need to reset the cron.job_run_details table. If data preservation is required, ensure you back up its contents before proceeding.

Execute the following SQL command via the SQL editor: TRUNCATE cron.job_run_details;