Re: Extended checkpoint times

TashkoP@kiwi.co.nz ("Peter Tashkoff") wrote: >I had a problem in November of checkpoints blowing out to 10 minutes or so = >during the evening like your manifestation. >I was advised from tech support that checkpoints can blow out two ways. >1. When checkpoint is requested, Online freezes all sessions for users not = >in a critical section and waits for remainder to exit critical section = >before freezing their sessions. >A critical section is most likely to be a physical write to disk. >2. If Online is carrying out some large unusual process, like a large = >table load, this can also cause checkpoints to blow out.=20 We get an extremely long checkpoint in a third situation. We run an oncheck -cI every Sunday on a 60 million row table. The checkpointassociated with the completion of this process generally exceeds 1000 seconds. >It is possible that a disk problem could be the cause. To investigate = >this possibility, during an interval when system is frozen do the = >following; >1. ID the sessions in critical sections. >2. onstat -g sessid to ID the tables being connected to. >3, ID the dbspace of the tables concerned. >4. ID the raw partition that this relates to. >In our case the sysadmin had been messing around with disks getting the = >machine ready for a solaris upgrade. I don't know why this might have = >affected online but the problem did go away after the disk got sorted out. = Barry Leb National Linen Service 1420 Peachtree Street MS #314 Atlanta, GA 30309 (404) 853-6119 (404) 853-6485 fax e-mail: barryleb@mindspring.com