Re: A caveat of partitioning tables in the document - Mailing list pgsql-hackers

From Fujii Masao
Subject Re: A caveat of partitioning tables in the document
Date
Msg-id CAHGQGwF6Fk63vQwK=M79DdNOdOKG6MRTyX0Vq1fZVdtQqKnFdQ@mail.gmail.com
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In response to A caveat of partitioning tables in the document  (Kasahara Tatsuhito <kasahara.tatsuhito@gmail.com>)
Responses Re: A caveat of partitioning tables in the document
List pgsql-hackers
On Wed, Aug 22, 2012 at 12:59 AM, Kasahara Tatsuhito
<kasahara.tatsuhito@gmail.com> wrote:
> Hi.
>
> The latest document (doc/src/sgml/ddl.sgml) says
> =======================================
> 2974    <itemizedlist>
> 2975     <listitem>
> 2976      <para>
> 2977       Constraint exclusion only works when the query's <literal>WHERE</>
> 2978       clause contains constants.  A parameterized query will not be
> 2979       optimized, since the planner cannot know which partitions the
> 2980       parameter value might select at run time.  For the same reason,
> 2981       <quote>stable</> functions such as <function>CURRENT_DATE</function>
> 2982       must be avoided.
> 2983      </para>
> 2984     </listitem
> =======================================
> but in my understanding, this problem will be solved on 9.2 (with
> parameterized plans).
>
> Or some issues still remain ?

At least this limitation "A parameterized query will not be optimized,
since the planner cannot know which partitions the parameter value
might select at run time." has been solved unless I'm missing something.
So we should just get rid of that sentence from the document.

Regards,

-- 
Fujii Masao



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