Re: Re: Free buffer requested

Chaos,

> I never thought of have a log_buffer 200M, a shared pool size 1G!Totally
confused!
> Log_buffer too big is totallly useless. And 1G of shared pool is hard to
image.100m should be enough for most database if the application is well written.

As everybody said log_buffer 200M is to big and useless. But shared pool size of 100M is only for small database having low workload. For busy OLTP that's not unusual to have shared pool 1G and more.

Ramon,
What is the problem? You didn't mention the symthoms. "free buffer requested" and "enqueue requests" have nothing to do with redo logs at all.
"free buffer requested" - about data block buffers "enqueue requests" - about rows and tables locking (should be slightly lower then " enqueue releases" ;)

If you just want to be "proactive", take a look at "redo log space wait" and "redo buffer allocation retries"

--
Alexnadre




> As for the redo logs, place different groups in the same disk is ok (if

have multiple member, place members into different disks ). What i suggest
is : can you do this operation with nologging ? Or can you move your log
file from fs to raw?


> Maybe this helps most

>

>

> Good luck!

>

>             chaos

>             chaospku_at_163.net

>

> zhu chao

> DBA of Eachnet.com

> 86-021-32174588-667

>

>

> дк 2002-06-19 10:34:00 You wrote:

> >Ramon,

> >

> >Are you talking about "redo log space requests"?

> >What about the value of "redo log space wait time"?  I think, that's the

> >statistic, you should be worried.

> >

> >Igor Neyman, OCP DBA

> >ineyman_at_perceptron.com

> >

> >

> >

> >----- Original Message -----

> >To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com>

> >Sent: Wednesday, June 19, 2002 1:18 PM

> >

> >

> >> Tks Igor for your answer,

> >>

> >> It's 200 MB, sorry, for log buffer.

> >>

> >> According to the v$sysstat view, the value of free buffer requested was

> >too

> >> high and increasing, so decided to add more, previously was 50 MB and

the


> >> same results.

> >>

> >> I checked the RTFM and said that increase the log_buffer parameter or

add


> >> more dbwriters.

> >>

> >> First I increased to 100MB, the same results, later 200MB and the same

> >> results also.

> >>

> >> That says that the problem is for other side, I'm going in the wrong

> >> direction.

> >>

> >> Don't know what else to check.  The process is running alone in the

> >server,

> >> just one connection.

> >>

> >> Ramon

> >>

> >>

> >> ----- Original Message -----

> >> To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com>

> >> Sent: Wednesday, June 19, 2002 11:03 AM

> >>

> >>

> >> > What is "200BBM" (for log buffer)?

> >> > If it's 200MB - it's huge!

> >> >

> >> > Igor Neyman, OCP DBA

> >> > ineyman_at_perceptron.com

> >> >

> >> >

> >> >

> >> > ----- Original Message -----

> >> > To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com>

> >> > Sent: Tuesday, June 18, 2002 9:33 PM

> >> >

> >> >

> >> >

> >> > Hi list,

> >> >

> >> > Scenario Sun 880 Solaris 8, Oracle 8.1.7.3, 8GB Ram, 4 processors

> >> >

> >> > Redo logs 200MB size 4 groups in 1 disk

> >> > DBWriter = 2

> >> > log buffer 200 BM

> >> > Shared Pool 1 GB

> >> > db block buffers 100,000

> >> > db block size 8K

> >> >

> >> > I started a process and checked the V$sysstat and get those values

are


> >> > extremely high

> >> >

> >> > free buffer requested 28938, enqueue requests 25035, redo writer

> >latching

> >> > time 0

> >> >

> >> > Data 1 volume stripe of 2 disk

> >> > Index 1 volume stripe of 2 disk -- differents

> >> > RBS 1 disk apart

> >> > Temp 1 disk apart

> >> >

> >> > What parameter should I check ?

> >> >

> >> >

> >> > TIA

> >> >

> >> > Ramon E. Estevez

> >

>

> --

> Please see the official ORACLE-L FAQ: http://www.orafaq.com

> --

> Author: chaos

>   INET: chaospku_at_163.net

>

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-- 
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-- 
Author: Alexandre Gorbatchev
  INET: alexandre.gorbatchev_at_avermann.de

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