The documentation states that modification to these may impact performance, but what modifications could be made?
Release : 12.x
Component : AUTOMATION ENGINE
The value for CommitCntDel (and CommitCnt) would need to be decided between the Administrator and the DBA.
This does limit the number of records deleted during a single transaction; having larger values requires larger rollback segments, but needs fewer commits/writes to the redo log (and vice versa).
Please note that CommitCnt is utilized for AH, RH, RT, MELD and CommitCntDel is utilized for all other tables.
As a start, review usage of CommitCnt, set CommitCntDel to the same value and monitor from there - if rollback space is sufficient and there are too many logswitches occurring, increase CommitCntDel.
For example, if enough space is available, a good start would be increasing the value from default 1000 to 5000 for both CommitCnt and CommitCntDel.
This should reduce a lot the time to delete/import several million records.