[Solved] Recursive CTE to walk up a network, but choosing path at junctions based on an attribute

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 tree_idx_to_node ON "tree" ("to_node");
The optimized query:
WITH RECURSIVE us_path AS (SELECT
        tree.id_reach,
        tree.from_node,
        tree.to_node 
    FROM
        tree 
    WHERE
        tree.to_node = 1 
    UNION
    ALL SELECT
        tr.id_reach,
        tr.from_node,
        tr.to_node 
    FROM
        tree AS tr 
    JOIN
        us_path AS usp 
            ON tr.to_node = usp.from_node) SELECT
            us_path.id_reach 
    FROM
        us_path

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* original question posted on StackOverflow here.