[Solved] Understanding Variations on Multiple Joins

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:

  1. Description of the steps you can take to speed up the query.
  2. The optimal indexes for this query, which you can copy and create in your database.
  3. An automatically re-written query you can copy and execute in your database.
The optimization process and recommendations:
  1. 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 artists_idx_id ON "artists" ("id");
CREATE INDEX paintings_idx_id ON "paintings" ("id");
CREATE INDEX saleitems_idx_saleid ON "saleitems" ("saleid");
CREATE INDEX sales_idx_customerid ON "sales" ("customerid");
The optimized query:
SELECT
        c.id,
        c.givenname,
        c.familyname,
        a.givenname,
        a.familyname 
    FROM
        customers c 
    JOIN
        sales s 
            ON c.id = s.customerid 
    JOIN
        saleitems si 
            ON s.id = si.saleid 
    JOIN
        paintings p 
            ON si.paintingid = p.id 
    JOIN
        artists a 
            ON p.artistid = a.id

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* original question posted on StackOverflow here.