Hi,

The job actually has two functions.
1. is to check the dbo.workflowSchedule table for scheduled workflows to run and the secondary but little known function is to check the dbo.WorkflowLog table and delete any logs that are older than 5 days. The dbo.WorkflowLog table is uses when verbose logging for Nintex has been used. If this table has a lot of rows in it this could cause the scheduler job to get stuck. If the dbo.workflowSchedule also has a lot of rows in it this could also cause the job to get stuck. If the dbo.workflowSchedule does have a lot of rows in it delete any row that has a next run date of 9999-12-31 23:59:59.997

More information can be found here:
https://community.nintex.com/t5/Best-Practices/The-Nintex-Workflow-Scheduler-Job/ta-p/86107

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