Question

I created a query, that collects data from two tables, summs them up and shows the count of the cases and the total summ:

SELECT
    count(ut.id) AS total
    , ( SUM(internal_account) - SUM(( SELECT
            SUM( ub.bill_summs )
        FROM
            u_billing ub
        WHERE
            ub.bill_types = 'correction'
            AND ub.contract_id = ut.contract_id
      )) ) AS summ
FROM  
    u_transactions ut
WHERE
    ut.nulled = 0
    AND ut.type = 'comission'
    AND ut._status = 'not_paid'
    AND DATE( ut.add_timestamp ) = DATE( '2012-05-11' );

but it is really slow. On test cases it gave this result:

+-------+-------+
| total | summ  |
+-------+-------+
|   182 | 15105 |
+-------+-------+
1 row in set (4.13 sec)

It is 4.13 seconds on 182 cases and for only 1 day, but my live server has over 600k cases, so this will be extremely slow.

Any ideas, how I can rewrite the query for better performance?

---

Solution with remade query(ies):

DELETE FROM tmpContractSums;
INSERT INTO tmpContractSums
SELECT
    ub.contract_id
    , SUM( ub.bill_summs ) AS bill_summs
FROM
    u_billing ub
WHERE
    ub.bill_types = 'correction'
GROUP BY ub.contract_id;

SELECT
    count(ut.id) AS total
    , ( SUM(internal_account) - SUM(bill_summs) )
FROM  
    u_transactions ut
LEFT JOIN tmpContractSums t ON ut.contract_id = t.contract_id
WHERE
    ut.nulled = 0
    AND ut.type = 'comission'
    AND ut._status = 'not_paid'
    AND ut.add_timestamp BETWEEN '2012-05-11 00:00:00' AND '2012-05-11 23:59:59';

Execution time: 500ms

PS: Since I can’t drop tables with webuser I just created the table:

CREATE TABLE tmpContractSums AS SELECT contract_id, bill_summs FROM u_billing WHERE 1 = 0;

and the I’m deleting the records. Not as fast as drop, but still way faster then original.

Answer 1

How about simply using a “temporary” table?

DROP TABLE IF EXISTS tmpContractSums;
CREATE TABLE tmpContractSums AS SELECT contract_id, bill_summs FROM u_billing WHERE 1 = 0;
INSERT INTO tmpContractSums
SELECT
    ub.contract_id
    SUM( ub.bill_summs ) AS bill_summs
FROM
    u_billing ub
WHERE
    ub.bill_types = 'correction'
GROUP BY ub.contract_id;

SELECT
    count(ut.id) AS total
    , ( SUM(internal_account) - COALESCE(bill_summs, 0) )
FROM  
    u_transactions ut
LEFT JOIN tmpContractSums t ON ut.contract_id = t.contract_id
WHERE
    ut.nulled = 0
    AND ut.type = 'comission'
    AND ut._status = 'not_paid'
    AND ut.add_timestamp BETWEEN '2012-05-11' AND '2012-05-11 23:59:59';

This should be faster and if you want you can add indexes to the “temporary table” or make it a table with engine=memory if you have enough space.

Or:

DROP TABLE IF EXISTS tmpContractSums;
CREATE TABLE tmpContractSums AS SELECT contract_id, bill_summs FROM u_billing WHERE 1 = 0;
INSERT INTO tmpContractSums
SELECT
    ub.contract_id
    SUM( ub.bill_summs ) AS bill_summs
FROM
    u_billing ub
WHERE
    ub.bill_types = 'correction'
GROUP BY ub.contract_id;

SELECT
    count(ut.id) AS total
    , ( SUM(internal_account) - (SELECT bill_summs FROM tmpContractSums t WHERE ut.contract_id = t.contract_id ) )
FROM  
    u_transactions ut
WHERE
    ut.nulled = 0
    AND ut.type = 'comission'
    AND ut._status = 'not_paid'
    AND ut.add_timestamp BETWEEN '2012-05-11' AND '2012-05-11 23:59:59';