How to optimize this SQL query?
In case you have your own slow SQL query, you can optimize it automatically here.
For the query above, the following recommendations will be helpful as part of the SQL tuning process.
You'll find 3 sections below:
- Description of the steps you can take to speed up the query.
- The optimal indexes for this query, which you can copy and create in your database.
- An automatically re-written query you can copy and execute in your database.
The optimization process and recommendations:
- Avoid Subqueries (query line: 24): We advise against using subqueries as they are not optimized well by the optimizer. Therefore, it's recommended to join a newly created temporary table that holds the data, which also includes the relevant search index.
- Avoid Subqueries (query line: 30): We advise against using subqueries as they are not optimized well by the optimizer. Therefore, it's recommended to join a newly created temporary table that holds the data, which also includes the relevant search index.
- Avoid Subqueries (query line: 40): We advise against using subqueries as they are not optimized well by the optimizer. Therefore, it's recommended to join a newly created temporary table that holds the data, which also includes the relevant search index.
- Avoid Subqueries (query line: 47): We advise against using subqueries as they are not optimized well by the optimizer. Therefore, it's recommended to join a newly created temporary table that holds the data, which also includes the relevant search index.
- Avoid Subqueries (query line: 53): We advise against using subqueries as they are not optimized well by the optimizer. Therefore, it's recommended to join a newly created temporary table that holds the data, which also includes the relevant search index.
- Avoid Subqueries (query line: 63): We advise against using subqueries as they are not optimized well by the optimizer. Therefore, it's recommended to join a newly created temporary table that holds the data, which also includes the relevant search index.
- Avoid Subqueries (query line: 69): We advise against using subqueries as they are not optimized well by the optimizer. Therefore, it's recommended to join a newly created temporary table that holds the data, which also includes the relevant search index.
- Create Optimal Indexes (modified query below): The recommended indexes are an integral part of this optimization effort and should be created before testing the execution duration of the optimized query.
- Use Numeric Column Types For Numeric Values (query line: 7): Referencing a numeric value (e.g. 123) as a string in a WHERE clause might result in poor performance. Possible impacts of storing numbers as varchars: more space will be used, you won't be able to perform arithmetic operations, the data won't be self-validated, aggregation functions like SUM won't work, the output may sort incorrectly and more. If the column is numeric, remove the quotes from the constant value, to make sure a numeric comparison is done.
- Use Numeric Column Types For Numeric Values (query line: 15): Referencing a numeric value (e.g. 123) as a string in a WHERE clause might result in poor performance. Possible impacts of storing numbers as varchars: more space will be used, you won't be able to perform arithmetic operations, the data won't be self-validated, aggregation functions like SUM won't work, the output may sort incorrectly and more. If the column is numeric, remove the quotes from the constant value, to make sure a numeric comparison is done.
- Use Numeric Column Types For Numeric Values (query line: 16): Referencing a numeric value (e.g. 2) as a string in a WHERE clause might result in poor performance. Possible impacts of storing numbers as varchars: more space will be used, you won't be able to perform arithmetic operations, the data won't be self-validated, aggregation functions like SUM won't work, the output may sort incorrectly and more. If the column is numeric, remove the quotes from the constant value, to make sure a numeric comparison is done.
Optimal indexes for this query:
ALTER TABLE `available_material_printmode_config` ADD INDEX `available_printmod_idx_material_name` (`material_name`);
ALTER TABLE `available_material_printmode_config` ADD INDEX `available_printmod_idx_printer_name_printmode_name` (`printer_name`,`printmode_name`);
ALTER TABLE `available_materials` ADD INDEX `available_material_idx_material_name` (`material_name`);
The optimized query:
WITH printercheck AS (SELECT
EXISTS (SELECT
1
FROM
available_material_printmode_config
WHERE
available_material_printmode_config.printer_name = '123' LIMIT 1) AS p),
materialcheck AS (SELECT
CASE
WHEN available_material_printmode_config.material_name IS NULL THEN 0
ELSE 1 END AS m
FROM
available_material_printmode_config
WHERE
available_material_printmode_config.printer_name = '123'
AND available_material_printmode_config.printmode_name = '2' LIMIT 1) SELECT
m.name
FROM
material m
LEFT JOIN
available_material_printmode_config ac
ON ac.material_name = m.name
AND (
SELECT
printercheck.p
FROM
printercheck LIMIT 1
)
AND (
SELECT
m
FROM
materialcheck LIMIT 1
)
LEFT JOIN
available_materials am1
ON am1.material_name = m.name
AND (
(
SELECT
printercheck.p
FROM
printercheck LIMIT 1
) != 1
OR (
(
SELECT
printercheck.p
FROM
printercheck LIMIT 1
)
AND (
SELECT
m
FROM
materialcheck LIMIT 1
) != 1
)
)
WHERE
CASE
WHEN (
SELECT
printercheck.p
FROM
printercheck LIMIT 1
)
AND (
SELECT
m
FROM
materialcheck LIMIT 1
) THEN ac.printer_name = '123'
AND ac.printmode_name = '2'
ELSE am1.printer_name = '123' END