The log buffer is one meg right now. The application uses many, very small transactions. There is no possibility of combining the statements into a larger single transaction. There are no waits to allocate log buffer space. I have also considered setting the _log_io_size to less than 1/3 a meg instead of reducing the size of the buffer. The next thing I am going to try is to find out if there is a LGWR background write event. This would let me know if the buffer is ever filling to the point of background writes.
Thanks for the responses. Erik > -----Original Message----- > From: Jared Still [SMTP:[EMAIL PROTECTED]] > Sent: Saturday, June 22, 2002 1:30 PM > To: [EMAIL PROTECTED]; Erik Williams > Subject: Re: Log file synch / direct path writes > > > Just how large is your overly large log buffer? > > 10 meg? > > 100 meg? > > 1 Gig??? ( ok, I've never heard of one this big, > but you never know ;) > > Jared > > On Friday 21 June 2002 12:48, Erik Williams wrote: > > I have an instance that is waiting on log file synchs. I suspect that > the > > waits are a result of a overly large redo log buffer. There are also > > considerable waits on direct path writes. The redo logs are on QuickIO, > so > > I assume that the writes LGWR is writing asynchronously and not a source > of > > the log file synchs. I want to be sure that the log file synchs and > direct > > path writes are not related before I begin to experiment with the size > of > > the redo log buffer. How can I be sure that the waits are being caused > by > > DBWR and not LGWR? What are possible fixes for the direct path writes if > it > > is the DBWR causing them? Multiple DBWR? The datafiles are not on > QuickIO, > > just the redo. > > > > Thanks > > Erik -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Erik Williams INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
