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Re: Please help with performance problem

From: S V <sv1_at_mindspring.com>
Date: 1997/11/23
Message-ID: <01bcf7b2$d2ff0920$3d5c0c26@sfinance3>#1/1

Solution:
1. Increase the size of redo log files.
2. Make sure checkpoint and redo log switch

     happens no more often than once
     every 15 mins under max load.

3. Try to place redo logs on a raw partition/device.

The rule of thumb is:
the checkpoint (which normally
happens when redo logs get switched)
should occur NO MORE often
than once every 15 mins under max load.
That's what Oracle told me.
I'm running Oracle 7..3.3
and under max insert activity
I can get > 1 MB/s writes to redo logs. Hence I made them 600Mb (no kidding) in size each, and even then sometimes I get
redo log switch every 5-10 mins or so..
And (envy me) I can load 3-4 million rows with 120 columns (avg_row_len ~ 320 ) per hour. This is on RS6000 AIX box with 6x604e CPUs.

Cordially,
Serge

Gena <gshepin_at_webspan.net> wrote in article <3474BCD8.6CCACA32_at_webspan.net>...
> Hi.
>
> I am trying to tune an Oracle 7.3.3 running on an NT 4 server.
> This machine has 256Megs of Memory and dual 200MHZ processors.
> This machine is completely dedicated to Oracle and never has anything
> else running.
>
> I have been trying to tune it few a few days now.
> The selects seem to work fine, but updates, deletes and especially
> inserts seem to take much longer than I would think they should on such
> a machine.
>
> To insert 2500 records on a 4 field table (which has only about 2000
> records) takes 45 seconds to a minute.
> To update or delete the same # of records (the delete criteria is on an
> indexed field) takes 30-40 seconds.
> Basically, every operation that does any database changes seems to kill
> performance.
>
>
> I am trying anything I can think of to improve this performance but
> nothing seems to be working.
>
> The Data, indexes, and rollback tablespaces are all on separate drives.
>
> I have rebuilt the database with the following initorcl parameters:
>
> I changes all initorcl parameters to those of a Large Database, I also
> set
> cpu_count=2
> db_block_size=8192 (the maximum allowed on NT)
> shared_pool_size=12000000
> pre_page_sga = True (to ensure the entire SGA will be in memory)
>
> Then I rebuilt the database.
>
> I saw little if any improvement in performance (from the default install
>
> configuration) after the rebuild.
>
> Can somebody please tell me if I'm missing any important parameters to
> improve
> performance, or has any other suggestions, or best of all if someone has
> a similar
> hardware setup, can I please see you initorcl file.
>
> any help would be GREATLY appreciated..........
>
>
Received on Sun Nov 23 1997 - 00:00:00 CST

Original text of this message

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