Alexandre, > -- Assuming those tables (not original, but enought to get the point): > > CREATE TABLE prod.jobs ( > job_id serial PRIMARY KEY, > order_id integer NOT NULL REFERENCES sales.orders, > ); > > CREATE TABLE design.products ( > product_id serial PRIMARY KEY, > company_id integer NOT NULL REFERENCES sales.companies ON > UPDATE CASCADE, > product_code varchar(24) NOT NULL, > CONSTRAINT product_code_already_used_for_this_company UNIQUE > (company_id, product_code) > ); > > CREATE TABLE prod.jobs_products ( > product_id integer REFERENCES design.products ON UPDATE CASCADE, > ) INHERITS (prod.jobs); First off, let me say that I find this schema rather bizarre. The standard way to handle your situation would be to add a join table instead of inheritance for jobs_products: CREATE TABLE jobs_products ( job_id INT NOT NULL REFERENCES prod.jobs(job_id) ON DELETE CASCADE, product_id INT NOT NULL REFERENCES design.products(product_id) ON UPDATE CASCADE, CONSTRAINT jobs_products_pk PRIMARY KEY (job_id, product_id) ); Then this view: > CREATE VIEW prod.orders_jobs_view AS > SELECT job_id, order_id, product_code > FROM ( > SELECT *, NULL AS product_id FROM ONLY prod.jobs > UNION > SELECT * FROM prod.jobs_products > ) AS alljobs LEFT JOIN design.products ON alljobs.product_id = > products.product_id; Becomes much simpler, and better performance: CREATE VIEW prod.orders_jobs_view AS SELECT job_id, order_id, product_code FROM prod.jobs LEFT JOIN prod.jobs_products ON prod.jobs.job_id = prod.jobs_products.job_id LEFT JOIN design.products ON prod.jobs_products.product_id = design.products.product_id; > I imagine that somewhere down the road, this will get slow since there > is no index on the order_id. I tought of creating two indexes... With > the previous VIEW and database schema, will the following boost the > DB; as I don't know how PostgreSQL works internally: Yes. Any time you have a foreign key, you should index it unless you have a really good reason not to. -- --Josh Josh Berkus Aglio Database Solutions San Francisco
