RE: Indexes

Oh goody, indices, my favourite.

Indices can slow down select queries.
If you have too many (I know, a vague term) indices on a table you can confuse both the CBO and RBO. If this happens the explain plan will choose the "wrong" index even though it is quite obvious there is a more appropriate index to use. Dropping indices in this case can improve performance dramatically.

Jared wrote:
>The reverse key indexes are to reduce contention for
>inserts on PK index blocks in OLTP systems with high
>transaction rates.

>Sequential generated PK values will go into different
>index blocks.

On large, heavily inserted tables performance increases anywhere from 2 - 10 times
by using reverse key primary indices.

Remember indexing is an art not a science.

Dave

-- 
Dave Morgan
Senior Database Administrator
Internet Barter Inc.
www.bartertrust.com