Sql Server Programming :: SQL Server 2000 Views and Views containing Views


	SQL Server 2000 Views and Views containing Views I was wondering if anyone could shed any light on this. I am using SQL Server 2000. I start with 1 view (VIEW A) that uses a UNION statement that includes 2 queries. Each query is not too complicated (i.e. few joins but no subquery). I then run a report and it take a long time to run. So I decide to make 2 new views each with one query. Then I modify the original view (VIEW A) to use a UNION statement that combines the 2 views, rather than the queries. This runs much faster. I am surprised by this. Should I be? I have never been a fan of views of view because of the admin nightmare of too many views. But it seems like there is a performance advantage. Can this be true? Have you tried using UNION ALL? Union by default will remove duplicates and will slow down your select. Immy "Paul" <P@discussions.microsoft.com> wrote in message news:FADCC7BC-F18E-4D8B-A7E4-28642385C58B@microsoft.com... - Hide quoted text - >I was wondering if anyone could shed any light on this. I am using SQL >Server > 2000. > I start with 1 view (VIEW A) that uses a UNION statement that includes 2 > queries. Each query is not too complicated (i.e. few joins but no > subquery). > I then run a report and it take a long time to run. > So I decide to make 2 new views each with one query. Then I modify the > original view (VIEW A) to use a UNION statement that combines the 2 views, > rather than the queries. > This runs much faster. > I am surprised by this. Should I be? I have never been a fan of views of > view because of the admin nightmare of too many views. But it seems like > there is a performance advantage. Can this be true? Have you compared execution plans of setting #1 vs. setting #2? Therein may the answer lie. ML --- http://milambda.blogspot.com/