SQL Query 执行需要时间

Question

My table having 2 million records. I want to insert data in temp table and use that temp table in my procedure. But for insertion it's taking 30 seconds. Please suggest how to reduce the time? I cant show actual query. so my query is in this format.

Note: I had already used CTE.

;With Tmp_TableName
        as
        (
        SELECT  T1.A, T1.B, T1.C, T1.D, T1.E, T1.F, T1.G , T1.H
        FROM    TableName T1 WITH(NOLOCK)
        WHERE   T1.A = 1
                AND CONVERT( NVarchar, T1.H, 111) <= CONVERT( NVarchar, getdate(), 111)

        )
    SELECT  *
    FROM    Tmp_TableName T1 WITH(NOLOCK);

Answer 1

I would recommend fixing your WHERE clause:

WHERE T1.A = 1 AND
      T1.H < DATEADD(DAY, 1, CAST(GETDATE() as DATE)0

This can then take advantage of an index on TABLE1(A, H) .

Answer 2

You can just filter out with cast() :

WHERE T1.A = 1 AND
      T1.H <= CAST(GETDATE() AS DATE) -- This assumes `T1.H` has no time. (i.e. 00:00:00);

If in your SELECT statement has any field which has varchar/nvarchar(max) type then it might run to slow, you can exclude it & check further.

However, you didn't included any table structure with indexes so, it is difficult to answer anyone.