Poor query performance with BETWEEN

Question

I'm using Oracle Reports 6i.
I needed to add Date range parameters (Starting and Ending dates) to a report. I used lexicals in the Where condition to handle the logic.
If no dates given,
Start_LEX := '/**/' and
End_LEX := '/**/'
If Start_date given,
Start_LEX := 'AND t1.date >= :Start_date'
If End_date given,
End_LEX := 'AND t1.date <= :End_date'
When I run the report with no dates or only one of the dates, it finishes in 3 to 8 seconds.
But when I supply both dates, it takes > 5 minutes.
So I did the following
If both dates are given and Start_date = End date,
Start_LEX := 'AND t1.date = :Start_date'
End_LEX := '/**/'
This got the response back to the 3 - 8 second range.
I then tried this
if both dates are given and Start_date != End date,
Start_LEX := 'AND t1.date BETWEEN :Start_date AND :End_date'
End_LEX := '/**/'
This didn't help. The response was still in the 5+ minutes range.
If I run the query outside of Oracle Reports, in PL/SQL Developer or SQLplus, it returns the same data in 3 - 8 seconds in all cases.
Does anyone know what is going on in Oracle Reports when a date is compared with two values either separately or with a BETWEEN? Why does the query take approx. 60 times as long to execute?

Answer 1

Hi,
Observe access plan first by using BETWEEN as well as using <= >=.
Try to impose logic of using NVL while forming lexical parameters.
Adinath Kamode