Re: Oracle Performance

Kenneth schrieb:
>
> I am new to Oracle. I am suprise why perfermance is so
> bad?
> My company have an application getting a livefeed on 9600
> modem, and write the data in oracle by ODBC.
>
> The configuration of hardware and software is:
> Oracle 7.3.3.3. Workgroup Server:
> run on PII 350, AMI RAID5 Controller, IBM SCSI-II harddisks,
> 256M RAM, NT Server 4.0.
>
> LiveFeed Machine:
> run PII 350, 128M RAM, IDE harddisk, VB6 ODBC program.
>
> There are around 4 or 5 tables to be updated in the server,
> and their rows size are less than 2000 and some 30 fields.
>
> The SQL of VB is a simple update based on on primary key.
> There are about 500 updates per mintues.
>
> I wonder why the cpu usage of oracle is always 80-90%. And
> it didnot drop even when there is no data from the feed.
>
> What exactly Oracle is doing???
>
>

Hi,

four points worth to be looked at:

• How much cache does your RAID controller has? We encountered massive probs with a double pentium and a RAID having only 4MB cache. Both processor didn't nothing than fighting for the cache at 90-100% of CPU-ussage. Increasing the cache to 16/32 MB solved the prob. Since you have only one CPU this may not apply to your situation. But concerning RAID-cache, for the sake of consistency be sure you've the write through option set to on.
• Are your redo logs right sized? Are there enough log files in your groups, so that no contention occurs? Check the oracle allert file for allocation errors.
• Are your rollback segments right sized to keep all the transaction data?
• Try out writing SP's to insert the data into your table. Call these SP's either via ODBC or oracle objects for OLE. You'll get insert stats with parameters which are handled more efficient (parsed only one time, used frequently), than insert stats dynamically created by VB, which must be parsed each for its own.

HTH
Matthias

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Matthias.Gresz_at_Privat.Post.DE

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