Re: When does LGWR flush the ebuffer?

From: Mark D Powell <Mark.Powell_at_eds.com>
Date: 22 Apr 2003 07:34:46 -0700
Message-ID: <2687bb95.0304220634.1d02a5e3@posting.google.com>

Peter <peter_at_nomorenewsspammin.ca> wrote in message news:<kur9avoueoqsaaepunact06qcraj7vla7o_at_4ax.com>...
> The LGWR flushes the buffer every 3 seconds, or when there is a
> commit.
> Does it ever flush it when the buffer is 1/3 or totally full?
> If it flushes it when buffer 1/3 full, then it will never get filled
> up?

From the version 9 Concepts manual:
LGWR writes one contiguous portion of the buffer to disk. LGWR writes:

A commit record when a user process commits a transaction

Redo log buffers

Every three seconds
When the redo log buffer is one-third full When a DBWn process writes modified buffers to disk, if necessary

Oracle would never want the log buffer to be full so writing at 1/3 full without a commit would seem to be about right if you wanted to keep up with additonal data coming into the log buffer.

HTH -- Mark D Powell -- Received on Tue Apr 22 2003 - 09:34:46 CDT