Calculate Batch with Resource Option: Specific Resources

When users submit Calculate Batch by selecting Resource Option: SPECIFIC Resources, it takes more than 2 hours to complete. However, if Calculation batch is submitted with Resource Option: ALL Resources -- it completes in less than 30 minutes.

When user selects Resource Option as SPECIFIC Resources, then clicks Add Resources button, in the next screen he Searches by Analyst. Doing this queries 800+ salesreps assigned to that Analyst. User will Select All the 800+ resources and submit Calculation. After request is scheduled, Calculate Batch will run for more than 1 hour before it launches any of the Transaction Batch Runners (for Revert, Classify, Rollup, Populate and Calculate stages of calculation). DBA has found there are 2 long running queries that Calculate Batch runs before it kicks off Transaction batch runners.