First rows retrieving slowly when there are no records.

Question

Hi, In a Web Application, I´m using a query to retrieve the last records on a table, by user who created them. The query uses the FIRST_ROWS hint to retrieve faster the records, as there are users that have lots of records on the table. It looks like this:
select * from(SELECT /*+ FIRST_ROWS*/ * FROM HISTORY WHERE USER_ID ='CC71312667'
ORDER BY CREATE_DATE DESC) where rownum<=7;
The usage of the hint works marvels in response times with those users with lots of records, but when the user has no records at all (i.e. the query won´t retrieve any records), the performance is actually poorer than not using the hint.
Is there any way to make the query retrieve records fast in both cases?
I was thinking in doing a previous query to ask if the user has records (using count)... but I would like to avoid this if possible.
Thanks for any help you can give me.
Message was edited by:
jvega

Answer 1

Are there any indexes on any columns of the table 'HISTORY'?
Are statistics estimated/computed for the table and indexes(if any on it)?
What version of Oracle do you use?
Could you post the execution plan(s) for your case?
Do you often delete data from table 'HISTORY'?