Skip to Main Content

Breadcrumb

Connor and Chris will both be at AI World from October 12 to October 17 , the premier Oracle conference of 2025. If you're in Vegas, please come say Hi or pop into our sessions

Question and Answer

Chris Saxon

Thanks for the question, Waldo.

Asked: August 04, 2022 - 8:16 pm UTC

Last updated: August 05, 2022 - 1:18 pm UTC

Version: 0

Viewed 10K+ times! This question is

You Asked

If I have an index, for example, by CD_CLIENT, CD_COMMOD, CD_MERCAD, and there is a query that uses them with TRIM. So:
.......
WHERE
TRIM( CUSTOMER_CD ) = ...
AND TRIM(CD_COMMOD) = ...
AND TRIM(CD_MARKET) = ...


Should I make another index that has the TRIM ?
Or is that enough?

Thank you very much!!

and Chris said...

Should I make another index that has the TRIM ?


Yes!

Applying any function to a column in the WHERE limits the optimizer's ability to use indexes on them.
TRIM is a function
=> This limits the optimizer's ability to use indexes.

That said, a better solution would be to avoid using TRIM() altogether - assuming this is possible.

Is this answer out of date? If it is, please let us know via a Comment
more

Connor and Chris don't just spend all day on AskTOM. You can also catch regular content via Connor's blog and Chris's blog. Or if video is more your thing, check out Connor's channel and Chris's channel from their Youtube channels. And of course, keep up to date with AskTOM via the official twitter account.

More to Explore

Design

New to good database design? Check out Chris Saxon's full fundamentals class.