От: Mark Kirkwood
Тема: Re: Hints proposal
Дата: ,
Msg-id: 45337C56.8000209@paradise.net.nz
(см: обсуждение, исходный текст)
Ответ на: Re: Hints proposal  ("Craig A. James")
Ответы: Re: Hints proposal  (Csaba Nagy)
Список: pgsql-performance

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Hints proposal  ("Jim C. Nasby", )
 Re: Hints proposal  (Bruce Momjian, )
  Re: Hints proposal  (Heikki Linnakangas, )
   Re: Hints proposal  (Tom Lane, )
   Re: Hints proposal  ("Jim C. Nasby", )
 Re: Hints proposal  ("Joshua Marsh", )
  Re: Hints proposal  ("Bucky Jordan", )
   Re: Hints proposal  (Robert Treat, )
    Re: Hints proposal  (Tom Lane, )
     Re: Hints proposal  (Robert Treat, )
  Re: Hints proposal  ("Jim C. Nasby", )
 Re: Hints proposal  (Tom Lane, )
  Re: Hints proposal  ("Merlin Moncure", )
  Re: [HACKERS] Hints proposal  ("Jim C. Nasby", )
   Re: [HACKERS] Hints proposal  (Josh Berkus, )
    Re: [HACKERS] Hints proposal  ("Jim C. Nasby", )
     Re: [HACKERS] Hints proposal  (Josh Berkus, )
      Re: [HACKERS] Hints proposal  ("Bucky Jordan", )
       Re: [HACKERS] Hints proposal  (Alvaro Herrera, )
      Re: [HACKERS] Hints proposal  ("Jim C. Nasby", )
       Re: [HACKERS] Hints proposal  (Tom Lane, )
       Re: [HACKERS] Hints proposal  ("Bucky Jordan", )
        Re: Hints proposal  ("Craig A. James", )
         Re: Hints proposal  (, )
         Re: Hints proposal  (Mark Kirkwood, )
          Re: Hints proposal  (Csaba Nagy, )
           Re: Hints proposal  (Brian Hurt, )
            Re: Hints proposal  (Bruce Momjian, )
            Re: Hints proposal  (Shaun Thomas, )
           Re: Hints proposal  (Mark Kirkwood, )
       Re: [HACKERS] Hints proposal  (Josh Berkus, )
        Re: [HACKERS] Hints proposal  ("Jim C. Nasby", )
         Re: [HACKERS] Hints proposal  (Alvaro Herrera, )
         Re: [HACKERS] Hints proposal  (Tom Lane, )
      Re: [HACKERS] Hints proposal  (Gregory Stark, )
    Re: Hints proposal  ("Craig A. James", )
    Re: [HACKERS] Hints proposal  ("Zeugswetter Andreas ADI SD", )
  Re: Hints proposal  (Csaba Nagy, )
   Re: [HACKERS] Hints proposal  (Josh Berkus, )
    Re: [HACKERS] Hints proposal  (Csaba Nagy, )
   Re: [HACKERS] Hints proposal  (Tom Lane, )
 Re: Hints proposal  (Jeff Davis, )
  Re: Hints proposal  (Csaba Nagy, )
   Re: Hints proposal  (Jeff Davis, )
    Re: Hints proposal  (Arjen van der Meijden, )
     Re: Hints proposal  (Tom Lane, )
      Re: Hints proposal  (Jeff Davis, )
     Re: Hints proposal  (Richard Broersma Jr, )
     Re: Hints proposal  (Christopher Browne, )
  Re: Hints proposal  ("Jim C. Nasby", )
   Re: Hints proposal  (Jeff Davis, )
 Re: [HACKERS] Hints proposal  (Andrew Sullivan, )
 Re: [HACKERS] Hints proposal  (Robert Treat, )

Craig A. James wrote:
>
>
> 2. Hints
>   a) On a aesthetic/theoretical level, hints suck.  They're ugly and rude
>   b) On a practical level, introducing hints will cause short- and
> long-term problems
>   c) Hints would help DBAs solve urgent problems for which there is no
> other solution

Pretty good summary!

Maybe there should be a 2d), 2e) and 2f).

2d) Hints will damage the ongoing development of the optimizer by
reducing or eliminating test cases for its improvement.
2e) Hints will divert developer resource away from ongoing development
of the optimizer.
2f) Hints may demoralize the developer community - many of whom will
have been attracted to Postgres precisely because this was a realm where
crude solutions were discouraged.

I understand that these points may seem a bit 'feel-good' and intangible
- especially for the DBA's moving to Pg from Oracle, but I think they
illustrate the mindset of the Postgres developer community, and the
developer community is, after all - the primary reason why Pg is such a
good product.

Of course - if we can find a way to define 'hint like' functionality
that is more in keeping with the 'Postgres way' (e.g. some of the
relation level statistical additions as discussed), then some of 2d-2f)
need not apply.

Best wishes

Mark








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