Re: Forcing Oracle to use an order in the from clause

From: Boris Panteleev <borispan_at_pop-milpitas.lsil.com>
Date: 1997/04/18
Message-ID: <3357F808.7DD3@pop-milpitas.lsil.com>#1/1

amit srivastava wrote:
>
> Can you force Oracle to use a particular table order in the
> from clause? Esp. if you have outer joins in them?
>
> Thank you for any information.
> -amit

You can.
By default Oracle reads the last table in the FROM clause FIRST. So when you optimize your queries make sure the order of the tables listed in FROM consistent with their row number and overall size. Also make sure that the most restrictive table is processed first..this will reduce significantly the overall number of join rows that are spooled in the memory/alternatively temp space.

Boris Received on Fri Apr 18 1997 - 00:00:00 CDT