If you've noticed oncheck
taking a long time to complete in IDS 9.40 and 10.0 you could be running into a known problem with missing read aheads. The defect, which has yet to be assigned an external APAR number, has the following description:
ONCHECK -CI NOT USING READ AHEADS THUS PERFORMANCE IS SLOW
The problem manifests as oncheck running normally immediately after bringing the engine up, but if executed when IDS has been online for some time oncheck no longer uses read-ahead and starts running slowly.
This problem is fixed in IDS 9.40.xC8W3
or later. Use defect reference CQ 3377
if you'd like to discuss this problem with tech support.
Note: A 'W' release represents a Post Interim Drop
containing bug fixes checked into the code line since the last interim release. There are typically 5 PIDs between two interim releases like (for example) UC8 and UC9.