Make SQL query faster and better

Question

I have a case where I need to collect sales statistics from a table with lots of aggregated data. The table has a few million entries, and the database itself is around 22Gb. Plenty of data to play with!

I have this working query, but I feel I should do this better - and it is also very slow.

I'm using PHP with sqlsrv extension on CentOS 7 to connect to a MSSQL database (ERP system).

My php variables in this query is set up like this:

$customer = '12345';
$year = '2016';
$compared_year = '2015';

So, as you may have guessed already, I'm collecting sales statistics for a given customer for each month of the year 2016 and 2015.

SELECT
ProdTr.CustNo AS customernummer,

(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $year . "01' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS sum_period_1,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $year . "02' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS sum_period_2,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $year . "03' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS sum_period_3,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $year . "04' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS sum_period_4,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $year . "05' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS sum_period_5,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $year . "06' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS sum_period_6,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $year . "07' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS sum_period_7,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $year . "08' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS sum_period_8,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $year . "09' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS sum_period_9,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $year . "10' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS sum_period_10,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $year . "11' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS sum_period_11,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $year . "12' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS sum_period_12,

(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $year . "01' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS dg_period_1,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $year . "02' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS dg_period_2,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $year . "03' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS dg_period_3,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $year . "04' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS dg_period_4,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $year . "05' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS dg_period_5,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $year . "06' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS dg_period_6,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $year . "07' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS dg_period_7,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $year . "08' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS dg_period_8,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $year . "09' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS dg_period_9,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $year . "10' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS dg_period_10,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $year . "10' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS dg_period_11,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $year . "11' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS dg_period_12,

(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "01' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_sum_period_1,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "02' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_sum_period_2,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "03' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_sum_period_3,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "04' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_sum_period_4,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "05' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_sum_period_5,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "06' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_sum_period_6,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "07' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_sum_period_7,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "08' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_sum_period_8,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "09' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_sum_period_9,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "10' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_sum_period_10,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "11' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_sum_period_11,
(SELECT SUM(DAm) AS 'Sum' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "12' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_sum_period_12,

(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "01' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_dg_period_1,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "02' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_dg_period_2,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "03' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_dg_period_3,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "04' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_dg_period_4,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "05' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_dg_period_5,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "06' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_dg_period_6,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "07' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_dg_period_7,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "08' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_dg_period_8,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "09' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_dg_period_9,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "10' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_dg_period_10,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "11' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_dg_period_11,
(SELECT (((SUM(DAm)-(SUM(StcCst)*-1))*100)/NULLIF(SUM(DAm),0)) AS 'DG' FROM ProdTr WHERE AcYrPr = '" . $compared_year . "12' AND ProdTr.TrTp = 1 AND ProdTr.CustNo = '" . $customer . "') AS compared_dg_period_12

FROM ProdTr

WHERE AcYrPr LIKE 201612
AND ProdTr.TrTp = 1
AND ProdTr.CustNo = '" . $customer . "'

GROUP BY ProdTr.CustNo, ProdTr.TrTp, ProdTr.AcYrPr

Note that the query works well, giving me the result i expect - but it is too slow on customers with many orders/transactions.

Any pointers on how to speed this up?

Thank you very much for your time!

Answer 1

Your query should be using conditional aggregation:

SELECT ProdTr.CustNo AS customernummer,
       SUM(CASE WHEN AcYrPr = '" . $year . "01' THEN DAm ELSE 0 END) as sum_period_1,
       SUM(CASE WHEN AcYrPr = '" . $year . "02' THEN DAm ELSE 0 END) as sum_period_2,
       . . .
WHERE AcYrPr LIKE 201612 AND ProdTr.TrTp = 1 AND
      ProdTr.CustNo = '" . $customer . "'
GROUP BY ProdTr.CustNo, ProdTr.TrTp;

Subqueries should not be necessary.