Re: Caching Problem in OPS

Sorry for my bad description first. Actually, I've three RS/6000 machines. Two of them (A & C) is formed a
cluster. The following table describes some information about each machine:

                         	Machine A       Machine B	Machine C
OS                      	AIX 4.1.5       	AIX 4.1.5	AIX 4.1.5
Physical memory          	1G              	256M		1G
Paging file             	640M            	256M		640
7.3.4.3 Oracle server   	Yes             	Yes		Yes
OPS option              	Yes             	No		Yes
SGA size                	300M            	27M		300M
DB block size		8K		4K		8K
Data file format		RAW		FS		RAW

Generally speaking, everything on Machine A is identical to Machine C. Parallel server on both machines can startup successfully at the same time. And run properly except the problem I described before. So OPS and HACMP parts should be OK.

At the first time, Machine A & C was used the same memory initial parameters as Machine B used. After the problem discovered, I've changed these parameters about 10 times more than the originals, but still no use. Then I stopped the OPS instance on Machine C, but again ... My further experiment is to remove the OPS instances and database on both machines, and reinstall only on Machine A. Afterwards, start the instance on Machine A without "Parallel" option and try ... Again still no help and no different. So I try to compare the execution plan on Machine A with one on Machine B. They are same. What can I do now???

Please help!

Peter Sharman <psharman_at_us.oracle.com> wrote in article <36E5615B.ED21090C_at_us.oracle.com>...
> I'm confused by what you ar trying to achieve with the Parallel Server
part.
> If you've installed it on one machine but not the other, you can't use
OPS.
> Are the two machines clustered? Parallel Server is only used in a
clustered
> configuration to access a single database on shared disk from two or more
nodes
> of the cluster. If that's not what you're trying to do, I'd remove OPS
from
> the equation first. You will be taking up unnecessary resources with the
DLM
> if nothing else.
>
> The problem, however, is probably not related to that. We need more
> information. Is anything else happening on Machine A that would flush
the data
> buffer cache? Are there other users doing things? Are the two machines
using
> different values for things like db_buffer_cache? How are the disks laid
out?
> etc. etc.
>
> Dicky wrote:
>
> > Hi everybody,
> >
> > I have two RS6000 machines.
> >
> > Machine A Machine B
> > --------- ---------
> > OS AIX 4.1.5 AIX 4.1.5
> > Phyical memory 1G 256M
> > Paging file 640M 256M
> > 7.3.4.3 Oracle server Yes Yes
> > OPS option Yes No
> > SGA size 300M 27M
> >
> > After restarting the Oracle server on both machines to clear all cache,
I
> > run an UNION SQL statment by SQLPLUS program. Due to advanced hardware
on
> > Machine A, it runs faster than Machine B (3mins vs. 9mins) in the first
> > run. However, the result seems to be abnormal when I re-run the same
> > statment in the same SQLPLUS session. Machine B only takes 1mins to
finish
> > in second run, but run time for Machine A remains as it is. Same
outcome
> > as re-running more.
> >
> > It seems that Machine A cannot take the caching advantage during
re-run.
> > I've tried to "startup parallel", "startup exclusive", "startup" Oracle
> > server with OPS option on Machine A, but still produces same result.
No
> > help!
> >
> > I would like to know why Oracle server with OPS option is so slow in
> > re-run. Is it MUST for OPS??
> >
> > Thanks in advance!
>
> --
>
>
> Regards
>
> Pete
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Peter Sharman Email: psharman_at_us.oracle.com
> WISE Course Development Manager Phone: +1.650.607.0109 (int'l)
> Worldwide Internal Services Education (650)607 0109 (local)
> San Francisco
>
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>
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> Corporation
>
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Received on Wed Mar 10 1999 - 10:59:34 CST