Weird query performance

I have a query against a view that is exhibiting some pretty strange performance problems Perhaps someone can fill me in on what exactly is happening.

If I execute this query:

select * from postview where col1='X' and miltime=1753 and airdate=981229;

we get total execution time of around 2 seconds.

If we then change any of the 'where' clauses, we get subsequent execution times of about .2 seconds (10 times faster!). This continues as long as we don't duplicate any of the queries previously run. If we do, then that query will take 2 seconds.

Why is it doing this? Shouldn't it be faster to retrieve data from previously cached statements? I don't understand why it takes so much longer if it reevaluates a statement that has already been run.

-Dave
dzuzga_at_isdinc.com Received on Fri Sep 17 1999 - 15:35:46 CDT