Question

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.

Optimal indexes for this query:

CREATE INDEX prs_idx_id ON prs (id);
CREATE INDEX qsn_idx_register_date ON qsn (register_date);

The optimized query:

SELECT
        qsn.code,
        (SELECT
            prs.display_name 
        FROM
            prs 
        WHERE
            prs.id = qsn.fk_prs) display_name,
        (SELECT
            prs.address 
        FROM
            prs 
        WHERE
            prs.id = qsn.fk_prs) address,
        (SELECT
            prs.tel 
        FROM
            prs 
        WHERE
            prs.id = qsn.fk_prs) tel 
    FROM
        qsn 
    WHERE
        qsn.register_date BETWEEN :x1 AND :x2

How to optimize this SQL query?

The optimization process and recommendations:

Optimal indexes for this query:

The optimized query:

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