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Home -> Community -> Usenet -> c.d.o.misc -> Re: Oracle Performances Problems
On Mon, 2 Nov 1998 20:45:40 +0100, orsano wrote
(in message <363E0BE4.DF87086E_at_inf.uniroma3.it>):
>
> Hi, We are experimenting severe performance problems (the client is very
> unhappy about it ) apparently due to the number of connections. As soon as
> we reach about 300 simuoltaneous connections (that is about 50 users) the
> performance drops down The workload is not heavly transactional (long
> transactions)
>
> We are working on the following platform:
>
> Client Power Builder 5.0 Microsoft ODBC 2.73 SQL*Net 2.3
>
> Network WAN
>
> Server SQL*Net 2.3 Oracle 7.3.3 AIX 4.1.2.
>
> The DB size is about 130 MB
>
> The tuning parameters we set are: SGA = 800 MB (2 GB Available) All of the
> table are cached (ALTER TABLE CACHE) 16 blocks of 4 KB for each read/write
> I/O operation (each AIX block is 4KB) Number of DBWR process = 4 Number of
> dispatcher = 40 Number of concurrent dispatcher running=40 Number of server
> processes : MIN=16, MAX=128 No disk striping
>
> When a performace problem occurs the server seems OK: I/O ok CPU idle 80%
> Cache hits about 99%
You have the complete db in memory so caching is not the problem. It occurs
when more users log on and the system containts long running tx. Did you check
locking ? With such a small db in so much memory full tablescans will not be a
problem but locking is.
run db with sql_trace = true and examine the tkprof output for check FTS's.
When the app is slow, also check locks by running $ORACLE_HOME/rdbms/utllockt
cheers
--
Ronald
I think so I mac ! Received on Mon Nov 02 1998 - 13:41:39 CST
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