Re: Upgrade Experiences from Oracle 7.3.X and Oracle 8.0.X to Oracle 8i

On Fri, 23 Feb 2001 18:17:53 GMT, "Douglas Kearney" <test_at_hotmail.com> wrote:

>slooooow. So, this is the next step. I also noticed that upgrading is
>basically taking dumps and re-importing into 8i after server has been
>upgraded. Are their any automated steps that I have missed or am I just
>crazy?? Wait, I just crazy, this is Oracle we are speaking about. The
>platforms that I am interested in are NT,2000, and HP Unix.
>

Hmmm, not so crazy, IMHO. :-)
Anyways, here is what I've found so far (7->8i and 8->8i): - Some of the earlier versions of 8i were quite buggy. 8.1.6 or later is the one to use.
- Working set sizes (memory) for 8i blow up like crazy unless you're using MTS and/or a few other tricks.
- Rowids are a worry inside the apps going from 7 to 8. PL/SQL code seems to be shielded from this in 8i if the code is using the datatype ROWID (automatically done).
- Handling of NULLS in PRO*C programs can be a problem. There is an option on the pre-compiler to behave like 7, but I'm more inclined to have the code fixed.
- SQL*Loader is much, much faster in 8i. Nearly 30% faster. Dunno why, but it is.
- I have yet to see major improvments in parallel INSERT/UPDATE/DELETE. But the parallel SELECT seems to work just fine in 8.
- The optimizer is a bit iffy on 8.0 working with partitioned tables and indexes. Most of the time it needs help. Unless you're prepared to do full ANALYZE of all columns *AND* indexes. - The optimizer in 8i is much better and takes better decisions. But some of the new hints are very badly explained, so thread carefully. - Even in 8.1.6, there are still a few surprise "bugs"...

Cheers
Nuno Souto
nsouto_at_bigpond.net.au.nospam
http://www.users.bigpond.net.au/the_Den/index.html Received on Sat Feb 24 2001 - 04:07:14 CST