query optimization

[Prasy]

Hello,

I have a query which executes in 3 secs in 7.3.4 and it takes 15 secs in 8i. I need to make use of dual processors which is with 8i. How should i change the query?? Should i use parallel hint??

[jdorlon]

Was it running in parallel on 7.3.4? If not, there is probabaly
something else different about the query. Look at the explain plan for it on both databases.

You can use a parallel hint, but if there is another way to
solve the problem (like adding an index or rewriting the
query to make better use of existing indexes) then that is
a better way to solve the problem.

-John
http://www.ezsql.net

[Prasy]

It is not running in parallel on 7.3.4
The explain plan seems to be same for both. The objects are same in both the machines.
So i doubted whether i am not using the hardware resources available.

[jdorlon]

Are the tables analyzed in both (or neither) databases?

Check to see if they are or not in your 7.3 database,
and make sure they are the same in your 8i database.

Also, if the 8i database is new, you may need to set some
of your init.ora parameters like shared_pool_size and
db_block_buffers - especially if they are at default values.

-John