Re: How does the planner execute unions?

From: Bruno Wolff III
Subject: Re: How does the planner execute unions?
Date: ,
Msg-id: 20050826204554.GB11078@wolff.to
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In response to: How does the planner execute unions?  (Chris Hoover)
List: pgsql-performance

On Fri, Aug 26, 2005 at 16:14:18 -0400,
  Chris Hoover <> wrote:
> Hopefully a quick question.
>
> In 7.3.4, how does the planner execute a query with union alls in it?
>
> Does it execute the unions serially, or does it launch a "thread" for
> each union (or maybe something else entirely).

Postgres doesn't have parallel execution of parts of queries. So it is
going to do one part followed by the other part.


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