Re: Concurrent updates / low performance

leonardo_ladeira_at_yahoo.com (Leonardo Ladeira) wrote in message news:<698f7e0a.0209261925.505371a_at_posting.google.com>...
> Hi,
>
> I hope anybody can help me on this issue....
>
> I use Oracle 8 running over AIX 4.3
>
> My application has only one table and a lot of concurrent updates (up
> to 15 per second). I made an embedded SQL function using host arrays
> to update a couple of rows (aprox 86) from the table.
>
> When I call this function once (1 single thread), it takes aprox 0.8s
> to execute.
>
> However, if I have 15 different threads calling this function at the
> same time, one single update can take up to 12 seconds!!! And all the
> 15 updates are related to DIFFERENT rows. The fastest update from the
> 15 takes at least 6 seconds!

A dumb question, which may serve only to highlight my ignorance... How many processors in your box?

I'm assuming your query is primarily bound on one device (either disk or CPU). If there's only 1 CPU, 15 threads, each of which require 0.8s of CPU (or 0.8s of disk access) would take exactly 12s. If there's only 1 processor in the box, your total time won't go down significantly.

Justin Cave Received on Sat Sep 28 2002 - 02:01:52 CEST