Question

I have an SP that takes 10 seconds to run about 10 times (about a second every time it is ran). The platform is asp .net, and the server is SQL Server 2005. I have indexed the table (not on the PK also), and that is not the issue. Some caveats:

• usp_SaveKeyword is not the issue. I commented out that entire SP and it made not difference.
• I set @SearchID to 1 and the time was significantly reduced, only taking about 15ms on average for the transaction.
• I commented out the entire stored procedure except the insert into tblSearches and strangely it took more time to execute.

Any ideas of what could be going on?

set ANSI_NULLS ON  go  ALTER PROCEDURE [dbo].[usp_NewSearch]    @Keyword VARCHAR(50),    @SessionID UNIQUEIDENTIFIER,    @time SMALLDATETIME = NULL,    @CityID INT = NULL  AS  BEGIN    SET NOCOUNT ON;    IF @time IS NULL SET @time = GETDATE();      DECLARE @KeywordID INT;    EXEC @KeywordID = usp_SaveKeyword @Keyword;    PRINT 'KeywordID : '    PRINT @KeywordID    DECLARE @SearchID BIGINT;         SELECT TOP 1 @SearchID = SearchID      FROM tblSearches      WHERE SessionID = @SessionID       AND KeywordID = @KeywordID;      IF @SearchID IS NULL BEGIN          INSERT INTO tblSearches                (KeywordID, [time], SessionID, CityID)           VALUES                (@KeywordID, @time, @SessionID, @CityID)          SELECT Scope_Identity();    END    ELSE BEGIN          SELECT @SearchID    END    END 

Answer 1

Why are you using top 1 @SearchID instead of max (SearchID) or where exists in this query? top requires you to run the query and retrieve the first row from the result set. If the result set is large this could consume quite a lot of resources before you get out the final result set.

SELECT TOP 1 @SearchID = SearchID       FROM tblSearches      WHERE SessionID = @SessionID         AND KeywordID = @KeywordID; 

I don’t see any obvious reason for this – either of aforementioned constructs should get you something semantically equivalent to this with a very cheap index lookup. Unless I’m missing something you should be able to do something like

select @SearchID = isnull (max (SearchID), -1)   from tblSearches  where SessionID = @SessionID    and KeywordID = @KeywordID 

This ought to be fairly efficient and (unless I’m missing something) semantically equivalent.