Performance difference: SELECT from VIEW or not?

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От Alexandre Leclerc
Тема Performance difference: SELECT from VIEW or not?
Дата
Msg-id 1dc7f0e3041115151015e34130@mail.gmail.com
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Ответы Re: Performance difference: SELECT from VIEW or not?  (Tom Lane <tgl@sss.pgh.pa.us>)
Список pgsql-performance
I'm just currious about which is the best, if I have many query based
on the first one:

-- suppose this view (used many times):
CREATE VIEW prod.alljobs_view AS
  SELECT *
  FROM prod.jobs
    LEFT JOIN prod.jobs_products ON jobs.job_id = jobs_products.job_id;

-- suppose this other query:
CREATE VIEW prod.orders_jobs_view AS
  SELECT job_id, order_id, product_code
    FROM prod.alljobs_view
      LEFT JOIN design.products ON alljobs_view.product_id =
products.product_id;

-- would this be more effective on database side than:?
CREATE VIEW prod.orders_jobs_view AS
  SELECT job_id, order_id, product_code
    FROM prod.jobs
      LEFT JOIN prod.jobs_products ON jobs.job_id = jobs_products.job_id
      LEFT JOIN design.products ON jobs_products.product_id =
products.product_id;

Which is the best, or is there any difference? (I can't test it
myself, I have too few data).

Regards.

--
Alexandre Leclerc

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