regular expressions in oracle

[student_help]

Is there a setting which must be set in an Oracle database (11g) for the database to run regular expressions?

I have a stored procedure which has a regular expression in it. This stored procedure is in 2 database (development database and a UAT database), it is working on one and it isnt working on the other one. This is impacting my work as I have to fix something which is got from the result of running the regular expression.

Would someone please be able to give me an idea of how to go about looking into this myself? I have searched Google and I cant find anything about a configuration change needing to be made. This database was set up and the people who know anything about it has since left. The rest of the query is running as expected on the 2 machines except it just 'ignores' the regular expression. I have pulled down the version that is working on one machine so I know they are the same code.

[rski]

Are both DB the same version?
Is "compatible" parameter set to the same value on both db
Under sqlplus execute command

show parameter compatible
 

How do you call regexp, with owa_pattern procedure or regexp_* functions?
Show here the problematic query.

[student_help]

Thank you for your reply. You were correct the version were slight different. It is working now as expected.