Re: Performance Issue (8i to 9i migration)

"kong" <kongkong99_at_yahoo.com> wrote in message news:cc50806d.0405060023.195eb3be_at_posting.google.com...
> Hi All,
>
> Seems that 8i to 9i migration give me a big shock.
> While we were using 8i, it took 2minutes to execute a package/view.
> But 9i takes more than 3 hours..
> It doesn't make sense.
>
> So, I'm wondering is there any thing i've missed out?
> For example some queries can not run in proper way as it is in 8i?
> Or, there are major changes in queries that i need to do?
>
> Can someone please help me or provide me as much information ..
> I appreciate your help so much.
>

Hi Felicia,

Simplistically, you need to learn how to trace a session and see what's going on. The number of people that tune databases as if it's a game of pinning the tale on the donkey never ceases to amaze me. Learn to trace and take the blind fold off is the best advice I can give.

However, with my Gemini powers of mental telepathy, give me the pin and let's have a go ....

In 9i, there was a now undocumented parameter called "_b_tree_bitmap_plans" that changed it's default value from false to true. This has resulted in many sites complaining about sub-optimal execution plans after moving from 8i to 9i.

Did I at least hit near the donkey's bum ?

Good Luck

Richard Received on Thu May 06 2004 - 08:03:58 CDT