enq: US - contension

Hi ,

When the batch job is running in my database, I see enq: US - contension wait event in top 5. I have enfough space in my Undo TS and datafiles are in different mount points and those mount points are not using by any other TS.

If any one had this kind of issue in the past, please provide me Metalik ID or URL to refer.

Oracle V - 10.2.0.4
OS - SUN Sol 10
Memory - 8GB
Undo TS size - 25GB (only 6 GB being used when the batch jobs are running)
Undo Ret. - 15mins

Thanks,

did you put that into google, where the first few hits have some useful suggestion?

Hi Dave,

Thanks for your reply.

Yes, I did that before comming here. Every one ending up increasing Undo TS size. However, when the batch job is running, same time gather database stats job (default 10g scheduler job) and segment space advisor jobs are running. I have started digging from that end to see whether they are causing any contension.

Thanks,

FYI -

My issue seems like a Bug 7291739 - Contention with auto-tuned undo retention.

Thanks,