[Solved] Rolling average postgres

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 sensor_values_idx_sensor_id_ts ON "sensor_values" ("sensor_id","ts");
CREATE INDEX sensor_values_idx_ts ON "sensor_values" ("ts" desc);
The optimized query:
WITH s AS (SELECT
        sensor_values.value 
    FROM
        sensor_values 
    WHERE
        sensor_values.sensor_id = $1 
        AND sensor_values.ts >= (NOW() - INTERVAL '2 day')::timestamptz 
    ORDER BY
        sensor_values.ts DESC LIMIT 200) SELECT
        avg(s.value),
        var_samp(s.value) INTO last_window_average,
        last_window_variance 
    FROM
        s

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* original question posted on StackOverflow here.