От: Tom Lane
Тема: Re: Suspending SELECTs
Дата: ,
Msg-id: 4245.1137556941@sss.pgh.pa.us
(см: обсуждение, исходный текст)
Ответ на: Re: Suspending SELECTs  (Mark Kirkwood)
Ответы: Re: Suspending SELECTs  (Mark Kirkwood)
Список: pgsql-performance

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Suspending SELECTs  (Alessandro Baretta, )
 Re: Suspending SELECTs  (Tom Lane, )
  Re: Suspending SELECTs  (Alvaro Herrera <-ip.org>, )
   Re: Suspending SELECTs  (Tom Lane, )
  Re: Suspending SELECTs  ("Craig A. James", )
   Re: Suspending SELECTs  (Alessandro Baretta, )
    Re: Suspending SELECTs  ("Jim C. Nasby", )
    Re: Suspending SELECTs  (Mark Lewis, )
    Re: Suspending SELECTs  ("Craig A. James", )
  Re: Suspending SELECTs  (Alessandro Baretta, )
   Re: Suspending SELECTs  (Michael Stone, )
   Re: Suspending SELECTs  (Tom Lane, )
   Re: Suspending SELECTs  (, )
    Re: Suspending SELECTs  (Frank Wiles, )
    Re: Suspending SELECTs  (Mark Kirkwood, )
     Re: Suspending SELECTs  (Tom Lane, )
      Re: Suspending SELECTs  (Mark Kirkwood, )
    Re: Suspending SELECTs  (Alessandro Baretta, )
     Re: Suspending SELECTs  (Tino Wildenhain, )
     Re: Suspending SELECTs  (, )
      Re: Suspending SELECTs  (Alessandro Baretta, )
       Re: Suspending SELECTs  (Harry Jackson, )
        Re: Suspending SELECTs  (, )
   Re: Suspending SELECTs  (Josh Berkus, )
    Re: Suspending SELECTs  (Josh Berkus, )
     Re: Suspending SELECTs  (Alessandro Baretta, )
      Re: Suspending SELECTs  (August Zajonc, )
       Re: Suspending SELECTs  (Alessandro Baretta, )
 Re: Suspending SELECTs  (Mark Lewis, )

Mark Kirkwood <> writes:
> SELECT ... FROM table WHERE ... ORDER BY id LIMIT 20;

> Suppose this displays records for id 10000 -> 10020.
> When the user hits next, and page saves id=10020 in the session state
> and executes:

> SELECT ... FROM table WHERE ... AND id > 10020 ORDER BY id LIMIT 20;

> Clearly you have to be a little careful about whether to use '>' or '>='
> depending on whether 'id' is unique or not (to continue using '>' in the
> non unique case, you can just save and use all the members of the
> primary key too).

This is actually fairly painful to get right for a multi-column key
at the moment.  It'll be much easier once I finish up the
SQL-spec-row-comparison project.  See this thread for background:
http://archives.postgresql.org/pgsql-performance/2004-07/msg00188.php

            regards, tom lane


В списке pgsql-performance по дате сообщения:

От: Alessandro Baretta
Дата:
Сообщение: Re: Suspending SELECTs
От: Marcos
Дата:
Сообщение: Simple Question of Performance ILIKE or Lower