От: Matthew Wakeling
Тема: Re: plpgsql arrays
Дата: ,
Msg-id: alpine.DEB.2.00.0904061222590.791@aragorn.flymine.org
(см: обсуждение, исходный текст)
Ответ на: Re: plpgsql arrays  (Tom Lane)
Список: pgsql-performance

Скрыть дерево обсуждения

plpgsql arrays  (Matthew Wakeling, )
 Re: plpgsql arrays  (Robert Haas, )
  Re: plpgsql arrays  (Matthew Wakeling, )
   Re: plpgsql arrays  (Tom Lane, )
    Re: plpgsql arrays  (Matthew Wakeling, )
     Re: plpgsql arrays  (Tom Lane, )
      Re: plpgsql arrays  (Matthew Wakeling, )
       Re: plpgsql arrays  (Matthew Wakeling, )
       Re: plpgsql arrays  (Tom Lane, )
        Re: plpgsql arrays  (Matthew Wakeling, )
        Re: plpgsql arrays  (Nathan Boley, )
    Re: plpgsql arrays  (Simon Riggs, )
     Re: plpgsql arrays  (Alvaro Herrera, )
     Re: plpgsql arrays  (Tom Lane, )
      Re: plpgsql arrays  (Matthew Wakeling, )
     Re: plpgsql arrays  (Matthew Wakeling, )
      Re: plpgsql arrays  (Robert Haas, )
 Re: plpgsql arrays  (Tom Lane, )
  Re: plpgsql arrays  (Matthew Wakeling, )
   Re: plpgsql arrays  (justin, )
    Re: plpgsql arrays  (Matthew Wakeling, )
     Re: plpgsql arrays  (justin, )
     Re: plpgsql arrays  (Tom Lane, )
      Re: plpgsql arrays  (Matthew Wakeling, )
   Re: plpgsql arrays  (Merlin Moncure, )
    Re: plpgsql arrays  (Tom Lane, )
     Re: plpgsql arrays  (Matthew Wakeling, )
      Re: plpgsql arrays  (Tom Lane, )
 Re: plpgsql arrays  (Merlin Moncure, )
  Re: plpgsql arrays  (Merlin Moncure, )
   Re: plpgsql arrays  (Matthew Wakeling, )
    Re: plpgsql arrays  (Merlin Moncure, )

On Fri, 3 Apr 2009, Tom Lane wrote:
> Simon Riggs <> writes:
>> On Fri, 2009-04-03 at 10:04 -0400, Tom Lane wrote:
>>> I don't actually believe that a standard merge join algorithm will work
>>> with an intransitive join condition ...
>
>> I think it's a common enough problem that having a non-standard join
>> algorithm written for that case would be interesting indeed.
>
> Sounds like a great PhD thesis topic.

I agree it'd be very cool to have a non-standard join algorithm for this
built into Postgres. However it is nowhere near complicated enough for a
PhD thesis topic.

I'm just putting the finishing touches on a plpgsql implementation - in
order to perform the join on a asymmetric set of ranges, you just need to
keep two separate history lists as you sweep through the two incoming
streams. This would be sufficient for range constraints.

Matthew

--
Surely the value of C++ is zero, but C's value is now 1?
  -- map36, commenting on the "No, C++ isn't equal to D. 'C' is undeclared
  [...] C++ should really be called 1" response to "C++ -- shouldn't it
  be called D?"


В списке pgsql-performance по дате сообщения:

От: Scott Marlowe
Дата:
Сообщение: Re: Forcing seq_scan off for large table joined with tiny table yeilds improved performance
От: Lists
Дата:
Сообщение: Re: Best replication solution?