Question

I have this SQL query but its running soo slow,

SELECT 
    wr.wr_re_id as ReID, 
    sum(wr.wr_total) as PRTotal 
FROM 
    Workorder2 w
    INNER JOIN 
    Workorder_Row2 wr ON wr.wr_wo_id = w.wo_id
WHERE 
    (w.wo_type = 1 or w.wo_type = 2)
    AND wr.wr_row_type = 2
    AND w.wo_lo_id like '%'
    AND w.wo_date_time >= '2010-01-01' 
    AND w.wo_date_time <= '2010-01-31'
    AND wr.wr_wo_id IN
        (SELECT 
            wr2.wr_wo_id 
        FROM 
            Workorder_Row2 wr2 
            INNER JOIN Workorder2 w2 ON w2.wo_id = wr2.wr_wo_id 
            AND w2.wo_date_time >= '2010-01-01' 
            AND w2.wo_date_time <= '2010-01-31' 
        WHERE 
            wr2.wr_row_type = 1)
GROUP BY 
    wr.wr_re_id

any advice how I can speed it up? it takes almost 1min to execute.
I think the problem is with the AND wr.wr_wo_id IN (SELECT ... but i need this to know if there are product sales on the same workorder that contains a threatment.

Answer 1

Firstly, have a look at your execution plan. It’s hard for us to optimize it as we don’t know your data.

The thing that jumps out the most is the wr.wr_wo_id IN (SELECT...) part. This would be far more efficient as a join, like this:

SELECT wr.wr_re_id as ReID, sum(wr.wr_total) as PRTotal 
FROM Workorder2 w
    INNER JOIN Workorder_Row2 wr on wr.wr_wo_id = w.wo_id
    INNER JOIN (
        SELECT DISTINCT wr2.wr_wo_id
        FROM Workorder_Row2 wr2 
            INNER JOIN Workorder2 w2 on w2.wo_id = wr2.wr_wo_id 
        WHERE w2.wo_date_time >= '2010-01-01' 
            AND w2.wo_date_time <= '2010-01-31'
            AND wr2.wr_row_type = 1
    ) T ON T.wr_wo_id = wr.wr_wo_id
WHERE (w.wo_type = 1 or w.wo_type = 2)
    AND wr.wr_row_type = 2
    AND w.wo_lo_id like '%'
    AND w.wo_date_time >= '2010-01-01' AND w.wo_date_time <= '2010-01-31'
GROUP BY wr.wr_re_id

It is worth considering whether it would help to add indices. It depends on how often you update/insert into/delete from those tables, and how selective each column is.

ADDITIONAL:

To do the reverse, i.e. to replace WHERE wr.wr_wo_id NOT IN (SELECT...), you would use:

SELECT wr.wr_re_id as ReID, sum(wr.wr_total) as PRTotal 
FROM Workorder2 w
    INNER JOIN Workorder_Row2 wr on wr.wr_wo_id = w.wo_id
    LEFT JOIN (
        SELECT DISTINCT wr2.wr_wo_id
        FROM Workorder_Row2 wr2 
            INNER JOIN Workorder2 w2 on w2.wo_id = wr2.wr_wo_id 
        WHERE w2.wo_date_time >= '2010-01-01' 
            AND w2.wo_date_time <= '2010-01-31'
            AND wr2.wr_row_type = 1
    ) T ON T.wr_wo_id = wr.wr_wo_id
WHERE T.wr2.wr_wo_id IS NULL
    AND (w.wo_type = 1 or w.wo_type = 2)
    AND wr.wr_row_type = 2
    AND w.wo_lo_id like '%'
    AND w.wo_date_time >= '2010-01-01' AND w.wo_date_time <= '2010-01-31'
GROUP BY wr.wr_re_id

However, it is more readable and (I would guess, though try it) more efficient to use:

SELECT wr.wr_re_id as ReID, sum(wr.wr_total) as PRTotal 
FROM Workorder2 w
    INNER JOIN Workorder_Row2 wr on wr.wr_wo_id = w.wo_id
WHERE (w.wo_type = 1 or w.wo_type = 2)
    AND wr.wr_row_type = 2
    AND w.wo_lo_id like '%'
    AND w.wo_date_time >= '2010-01-01' AND w.wo_date_time <= '2010-01-31'
    AND NOT EXISTS (
        SELECT NULL
        FROM Workorder_Row2 wr2 
            INNER JOIN Workorder2 w2 on w2.wo_id = wr2.wr_wo_id 
        WHERE w2.wo_date_time >= '2010-01-01' 
            AND w2.wo_date_time <= '2010-01-31'
            AND wr2.wr_row_type = 1
            AND wr2.wr_wo_id = wr.wr_wo_id
    )
GROUP BY wr.wr_re_id