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:
- 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.
- Remove Redundant Left Joins (modified query below): Redundant LEFT JOINs (e.g. `DATABASE_INFM`) were detected in the query. Removing them will result in a performance improvement. In some cases, JOINs become redundant after an optimization is applied, such as when converting OR conditions to a UNION clause.
Optimal indexes for this query:
CREATE INDEX database_pik_idx_id ON linkedserver02.DATABASE_PIK (id);
The optimized query:
SELECT
LTRIM(RTRIM(table1.a)) AS column1,
table2.b COLLATE Latin1_General_CI_AS AS column2,
table1.c AS column3,
CAST(table3.d AS DATETIME) AS column4,
'XXXXXX' AS column5
FROM
[linkedserver01].[DATABASE_IDN].[dbo].[dataForX] table1
LEFT OUTER JOIN
[linkedserver02].[DATABASE_PIK] AS table3
ON table3.id = table1.id