Since the installation of the database and the jobs, the job history of the whole instance is purged every 10 minutes with a retention between 3 and 4 hours.
Could you tell me which job performs this purge and is it possible to easily modify the retention?
There is no job that deletes the history. Like you have set this in your SQL Server to only keep a certain amount of rows which SQLWATCH fills up quickly becuase it runs often: