RE: Log file sync spike

• From: "Jonathan Lewis" <jonathan_at_xxxxxxxxxxxxxxxxxx>

*Over a period as long as fifteen minutes, it is possible for a change in timing (two jobs running concurrently instead of serially) to cause the redo synch times (and log file sync waits) to change dramatically while the redo write time doesn't
change at all.

Thank you, Jonathan.

"Dramatically" in my case is 10-15 times bigger wait time per period (I take snapshots at 20 min intervals.)
I am just wondering where lays the cause for this behavour. I can only speculate that the way LGWR batches log sync requests can cause a longer wait times.

Brgds, Laimis N.

Fyrirvari/Disclaimer
http://www.landsbanki.is/disclaimer

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