Re: immutable functions vs. join for lookups ?

От: Enrico Weigelt
Тема: Re: immutable functions vs. join for lookups ?
Дата: ,
Msg-id: 20050421192226.GB16548@nibiru.borg.metux.de
(см: обсуждение, исходный текст)
Ответ на: Re: immutable functions vs. join for lookups ?  (Jaime Casanova)
Ответы: Re: immutable functions vs. join for lookups ?  (Dawid Kuroczko)
Список: pgsql-performance

Скрыть дерево обсуждения

immutable functions vs. join for lookups ?  (Enrico Weigelt, )
 Re: immutable functions vs. join for lookups ?  (Tom Lane, )
  Re: immutable functions vs. join for lookups ?  (Enrico Weigelt, )
   Re: immutable functions vs. join for lookups ?  (Jaime Casanova, )
    Re: immutable functions vs. join for lookups ?  (Enrico Weigelt, )
     Re: immutable functions vs. join for lookups ?  (Dawid Kuroczko, )
 Re: immutable functions vs. join for lookups ?  (Dawid Kuroczko, )
 Re: immutable functions vs. join for lookups ?  ("Merlin Moncure", )
  Re: immutable functions vs. join for lookups ?  (Dawid Kuroczko, )
   Re: immutable functions vs. join for lookups ?  ("Jim C. Nasby", )
    Re: immutable functions vs. join for lookups ?  (Dawid Kuroczko, )
     Re: immutable functions vs. join for lookups ?  (Christopher Kings-Lynne, )
     Re: immutable functions vs. join for lookups ?  (Christopher Kings-Lynne, )
  Re: immutable functions vs. join for lookups ?  (Tom Lane, )
   Re: immutable functions vs. join for lookups ?  (Greg Stark, )
    Re: immutable functions vs. join for lookups ?  (Tom Lane, )
     Re: immutable functions vs. join for lookups ?  (Enrico Weigelt, )
      Re: immutable functions vs. join for lookups ?  (Dawid Kuroczko, )

* Jaime Casanova <> wrote:

<snip>
> Even if your data never changes it *can* change so the function should
> be at most stable not immutable.

okay, the planner sees that the table could potentionally change.
but - as the dba - I'd like to tell him, this table *never* changes
in practise (or at most there will be an insert once a year)

isnt there any way to enforce the function to be really immutable ?


cu
--
---------------------------------------------------------------------
 Enrico Weigelt    ==   metux IT service

  phone:     +49 36207 519931         www:       http://www.metux.de/
  fax:       +49 36207 519932         email:     
  cellphone: +49 174 7066481
---------------------------------------------------------------------
 -- DSL ab 0 Euro. -- statische IP -- UUCP -- Hosting -- Webshops --
---------------------------------------------------------------------


В списке pgsql-performance по дате сообщения:

От: Enrico Weigelt
Дата:
Сообщение: foreign key performance
От: "Shoaib Burq (VPAC)"
Дата:
Сообщение: Re: two queries and dual cpu (perplexed)