Re: Log file synch / direct path writes

2002-06-26 Thread Madhavan Amruthur
Hi, On a Sequent NUMA (now IBM) for a benchmark we used run queues where we bind the SGA to a set of processors. We had a 16 processor NUMA and we tied the SGA to 8 processors in the first test and user connections were all bound only to the 8 processors (2 quads) and then the second part of the t

Re: Log file synch / direct path writes

2002-06-24 Thread Ramon E. Estevez
That was my point. It doesn't matter that log_buffer = 100MB, if every 3 seconds LGWR will fire anyway even the buffer had only used 1k. tks Andrew - Original Message - To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Monday, June 24, 2002 3:23 PM > Don't forget,

Re: Log file synch / direct path writes

2002-06-24 Thread Ramon E. Estevez
Tks Dennis, Beth, Madhavan for your answer. Now I get it. Learned something new today about Oracle, that's my goal. Ramon - Original Message - To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Monday, June 24, 2002 1:53 PM > Hi Ramon, > > On Mon, 24 Jun 2002 09:

RE: Log file synch / direct path writes

2002-06-24 Thread Andrew Sit
Don't forget, LGWR also flushes the buffer every 3 seconds. Think about your transaction rate and whether you will make use of a large buffer space. My $0.02, Andy. -- Andrew Sit Systems Engineer DataMirror Corporation + 1 905 415 0310 (O) + 1 416 839 9908 (M) -Original Message- Sen

Re: Log file synch / direct path writes

2002-06-24 Thread Ramon E. Estevez
Dennis, 100MB archive log size. Ramon - Original Message - To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Monday, June 24, 2002 2:03 PM > Ramon, along the lines of Beth's idea here, how large are the archive logs > you are producing? > > Dennis Williams > DBA > L

RE: Log file synch / direct path writes

2002-06-24 Thread DENNIS WILLIAMS
Ramon, along the lines of Beth's idea here, how large are the archive logs you are producing? Dennis Williams DBA Lifetouch, Inc. [EMAIL PROTECTED] -Original Message- Sent: Monday, June 24, 2002 1:19 PM To: Multiple recipients of list ORACLE-L Ramon, For one thing, LGWR will write t

Re: Log file synch / direct path writes

2002-06-24 Thread Madhavan Amruthur
Hi Ramon, On Mon, 24 Jun 2002 09:28:21 -0800, "Ramon E. Estevez" <[EMAIL PROTECTED]> said: > What implications can cause having a big log buffer. > You want to check the tip from Steve Adams to understand how log buffer works and the implications of a big log buffer http://www.ixora.com.au/tip

RE: Log file synch / direct path writes

2002-06-24 Thread Seefelt, Beth
Ramon, For one thing, LGWR will write the log buffer when it is 1/3 full, or if it reaches 1MB. So, its useless to have the log buffer more than 3MB. The space beyond 3MB could never possibly be used. My .02 Beth -Original Message- Sent: Monday, June 24, 2002 1:28 PM To: Multiple r

Re: Log file synch / direct path writes

2002-06-24 Thread Ramon E. Estevez
Jared, Just to clear my thoughts, doubts and keep learning from the list. What implications can cause having a big log buffer. As I can remember, LGWR copy data from the log buffer to the redo logs when log buffer is 1/3 full, timeout, commit and a few more. So it will fire when the first one

RE: Log file synch / direct path writes

2002-06-24 Thread Erik Williams
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

Re: Log file synch / direct path writes

2002-06-22 Thread Greg Moore
> result of a overly large redo log buffer. How large is it? > How can I be sure that the [direct path write] waits > are being caused by DBWR and not LGWR? In v$session_wait, for the "direct path write" wait event P1 is the file number. Waits for DBWR will be associated with a different set o

Re: Log file synch / direct path writes

2002-06-22 Thread Jared Still
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 o

Re: Log file synch / direct path writes

2002-06-21 Thread Anjo Kolk
Make sure that the LGWR runs freely on a processor, without interference from other foreground processes. On sun you can create processor sets for example. Anjo. - Original Message - To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Saturday, June 22, 2002 2:08 AM >

RE: Log file synch / direct path writes

2002-06-21 Thread John Kanagaraj
Anjo, > Give the LGWR its own processor. I have don't once in a > particular benchmark > and reduced the log file sync wait time by a factor of 10. When you say 'Give the LGWR its own processor' did you mean that processor binding needs to be done? As per my understanding, processor binding ma

Re: Log file synch / direct path writes

2002-06-21 Thread Anjo Kolk
Give the LGWR its own processor. I have don't once in a particular benchmark and reduced the log file sync wait time by a factor of 10. - Original Message - To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Friday, June 21, 2002 9:48 PM > I have an instance that is w