SQL Server 2008 R2 查询

Question

I'm running the following query, but it is taking too long. Is there a way to make it faster or change the way the query is written?

Please help.

SELECT *
FROM   ProductGroupLocUpdate WITH (nolock)
WHERE  CmStatusFlag > 2
       AND EngineID IN ( 0, 1 )
       AND NOT EXISTS (SELECT DISTINCT APGV.LocationID
                       FROM CM_ST_ActiveProductGroupsView AS APGV WITH(nolock)
                       WHERE APGV.LocationID = ProductGroupLocUpdate.Locationid);

Answer 1

Try rewriting the query with a join

SELECT PGLU.* from ProductGroupLocUpdate PGLU WITH (NOLOCK) 
LEFT JOIN CM_ST_ActiveProductGroupsView APGV WITH (NOLOCK) 
        ON PGLU.LocationId = APGV.LocationID
WHERE APGV.LocationID IS NULL AND CmStatusFlag>2 AND EngineID IN (0,1)

Depending on how much data is in your table, check add indexes to LocationId (in both tables), CmStatusFlag and EngineID