Re: Want function to be called only once in query

> Add the MATERIALIZED keyword to the WITH statement

Many thanks Jim, that's just what I needed - that does the trick.

It's hard to keep abreast of these SQL changes. Thank goodness for mailing
lists!

Steve

On Thu, 16 Sept 2021 at 11:56, Jim Mlodgenski <jimmy76(at)gmail(dot)com> wrote:

> On Thu, Sep 16, 2021 at 4:51 AM Steve Pritchard <steve(dot)pritchard(at)bto(dot)org>
> wrote:
> >
> > I have a PL/pgSQL function that I want to call within a query, but the
> function is fairly expensive to execute so I only want it executed once
> within the query. However the planner seems to reorganize my query so that
> it calls the function for every row.
> >
> > We were previously on Pg 9.6 and this wasn't a problem then. But now
> that we have upgraded to Pg 13, the behaviour has changed.
> >
>
> The behavior for planning a CTE changed in PG12.
>
> > There must be a "proper" way to get the planner to call a function only
> once.
> >
> Add the MATERIALIZED keyword to the WITH statement
>

--
Steve Pritchard
Database Developer

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