Re: Taking advantage of reverse index?
Date: Wed, 01 May 2002 05:26:45 GMT
Message-ID: <B8F4CA9F.1FCBC%markbtownsend_at_attbi.com>
in article e17de08c.0204301008.70f548e1_at_posting.google.com, Ronnie Schnell at ronnie_at_twitch.mit.edu wrote on 4/30/02 11:08 AM:
> Yep...I understand the purpose of it. But as a side effect, if Oracle
> were to choose to take advantage of it, it could be used to greatly
> speed up performance of searches where there is a wildcard at the
> beginning. Apparently, they didn't choose to take advantage of
> that...
Hmm - I'm not sure you do understand. What you want is an index on a reversed key, not a reversed key index. Oracle does the latter declaritively, but not the former. However, if you do want to index on a reversed key, consider creating a function that reverses the key values, and then create a functional index on that. You will need to use the function on both sides of the query, and I'm not sure it will work for the LIKE, and you will probably have to deal with the % yourself. But may be an interesting idea. Received on Wed May 01 2002 - 07:26:45 CEST