Oracle SESSIONS Parameter value needs to be increased (Cause : ORA-00018 )
Noticed the following error in SM21 and also found out that that many background jobs got canceled.
Database error 18 at COM > ORA-00018: maximum number of sessions exceeded. Function COMMIT on connection R/3 failed. Error at DB Commit, return code 001024. Database error 18 at COM Perform rollback
While looking for a solution for the issue, understood that we need to change the SESSIONS parameter to a
(Solution Note : 398927 - ORA errors because dimensions of parameters are too small)
(As per the above note, we are trying to sort out the issue, which also says a lot of things in which one could be the reason for the error. But we finally got to know that SESSIONS parameter is the problem and should be made to a higher value.)
Currently our BW Production Server, the settings are as follows:
■ PROCESSES = 224
■ SESSIONS = 251
(For your information:
PROCESSES Formula u21D2 ABAP work processes * 2 + #J2EE server processes *<max-connections> +
PARALLEL_MAX_SERVERS + 40
SESSIONS Formula u21D2 2 * PROCESSES
As per the above thing, SESSIONS should be 224 * 2 which should be 448.
Hence we are planning to change the same to 448.
1. What other things(OS Side, DB side, + Oracle Parameters etc) should be considered
in order to change the SESSIONS to 448.
2. Is there any problems anticipated by changing the SESSIONS parameter.
Thanks & Best Regards
Mark Förster replied
1. the Oracle documentation speaks about two dependencies for the SESSIONS parameter: ENQUEUE_RESOURCES and TRANSACTIONS:
However I never changed these other parameters, I don't think they are relevant for SAP systems.
2. no problems anticipated, you simply have to raise the sessions parameter if you encounter ORA-00018 on SAP systems