Re: Poor performance after oracle 8i upgrade

rreeve_at_goldcoast.qld.gov.au (Ruth) wrote in message news:<7d088242.0409062036.c87f0e1_at_posting.google.com>...
> Hi All
>
> I am not a DBA, but a unix administrator.
>
> After our DBA's upgraded from oracle 8.0.5 to oracle 8.1.7.4 on our
> test server, we have noticed a big slow down in our application
> (acocobol). From ~10mins to ~45mins.
>
>
> Server info:
> HP Proliant ML350G3
> 1024MB Ram
> 1 x Intel Xeon 2.8GHz processor
> Unixware 7.1.1
>
>
> The DBA's have run a report which indicates an I/O problem.
>
> Total Wait
> wait Waits
> Event Waits Timeouts Time (cs)
> (ms) /txn
> ---------------------------- ------------ ---------- -----------
> ------ ------
> log file sync 90,709 0 123,003
> 14 1.0
> log file parallel write 90,719 0 121,555
> 13 1.0
>
>
>
> Our redo logs are on a mirror.
>
>
> We also have tried setting OPTIMIZER_FEATURES_ENABLE=8.0.0
> but no luck .....
>
>
> The DBA's tried the upgrade 2 different ways
> 1. upgrade original database from 8.0.5 to 8.1.7.4
> 2. built brand new database from scratch then importing the data.
>
> Both ways have the same performance problem.
>
>
> Does anyone have any idea why this is occurring on 8.1.7.4 and not on
> 8.0.5, and how we can fix it.
>
> thankyou
>
> regards
> Ruth

How about running some sql traces on some of the long running processes? How about running statistics? The optimizer in 8.1.7 could be choosing a different plan than the 8.0.5 optimizer.

Pete's Received on Tue Sep 07 2004 - 15:30:47 CEST