Upper() and Indexing

Someone has suggested to me that using the UPPER(column_name) function in the where clause of an Oracle query will force Oracle to ignore an index placed on column column_name. For example, in the following query there is an index on CORE_SITE_NAME.SITE_NAME. If it is true that using the column in the UPPER() function forces Oracle to ignore the index, the index on the SITE_NAME column would be ignored in the query.

SELECT CORE_SITE_NAME.SITE_ID
     FROM CORE_SITE_NAME
 WHERE UPPER(CORE_SITE_NAME.SITE_NAME) = 'ACME' ; Can anyone confirm / refute the claim that the index on the SITE_NAME column would not be used in the above query?

Thanks in advance.
Luke Gentry Received on Wed Jun 24 1998 - 17:37:51 CDT