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 In From Clause (modified query below): The database cannot properly optimize subqueries in the FROM clause. Therefore, we recommend to extract the subqueries to temporary tables, index them and join to them in the outer query.
The optimized query:
COALESCE(NULLIF(ROUND(((0.95 * (ROW_NUMBER() OVER (PARTITION
b.Score6 ASC) - 1)) / COALESCE(NULLIF(COUNT(*) OVER (PARTITION
a.Prefix ) - 1,
1)) + 0.005,
0.95) AS NewScore
es_temp1 AS a CROSS APPLY es_temp2 AS b