RE: log file sync wait

From: K Gopalakrishnan <kaygopal_at_yahoo.com>
Date: Mon, 05 May 2003 01:06:36 -0800
Message-ID: <F001.0058F2D0.20030505010636@fatcity.com>

Ganesh:

Not very true. Slower log files with bigger log buffers are the main cause for log file sync waits. THis typically happens during a transaction end, either commit or rollback will make others wait for the log file sync.

To reduce this, you can keep the redo logs in the fastest disk, use no-logging wherever you can, reduce the commits,tune the sessions/processes parameter. And also there is an underscore parameter which will completely eliminate the log_file_sync waits. But that is against the Oracle's implementation of the ACID property in the transactional database system. You can use them during batch loads, benchmarks, _non_ production systems and test systems. But then the committed transactions are not necessarily committed transactions.

• ganesh_raja_at_non.agilent.com wrote:
  > Ur Log file sync wait is mainly because your Log Buffer is small and
  > every time Logwr Writes the redo into the Redo Logs your apps are
  > waiting for the sync to complete.
  >
  > Run Your Lgwr in Parallel using IO Slaves or use Async_IO parameter
  > ro control it from OS.
  > Increase the size of your LOGBuffer so that the ur App does not wait
  > for the syncs..
  >
  > HTH
  >
  > Best Regards,
  > Ganesh R
  

  ---

Have a nice day !!

---

Best Regards,
K Gopalakrishnan,
Bangalore, INDIA.

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Author: K Gopalakrishnan
  INET: kaygopal_at_yahoo.com

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Received on Mon May 05 2003 - 04:06:36 CDT