[Solved] Update in PostgreSQL performance relative to Select

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.
  2. Prefer Inner Join Over Left Join (modified query below): We identified that one or more left joined entities (e.g. `carrier_volumes`) are used in the 'where' clause, in a way that allows to replace it with an optimized inner join. Inner joins can be fully optimized by the database, while Left joins apply limitations on the database's optimizer.
Optimal indexes for this query:
CREATE INDEX carrier_units_idx_carrier_id_date ON "carrier_units" ("carrier_id","date");
CREATE INDEX carrier_volumes_idx_vehicle_id_date_id ON "carrier_volumes" ("vehicle_id","date","id");
CREATE INDEX carriers_idx_id ON "carriers" ("id");
CREATE INDEX units_idx_carrier_id_id ON "units" ("carrier_vehicle_id","id");
CREATE INDEX volumes_idx_value ON "volumes" ("value");
The optimized query:
        units u 
        volumes v 
            ON v.value = u.value 
        carrier_units cu 
            ON cu.id = u.mccus_inspection_id 
        carriers c 
            ON c.id = cu.carrier_id 
        carrier_volumes cv 
            ON cv.vehicle_id = v.id 
            AND cv.carrier_id = c.id 
        u.carrier_vehicle_id IS NULL 
        AND cv.id IS NOT NULL 
        AND u.id = 115215784 
        AND cv.date = cu.date

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* original question posted on StackOverflow here.