Re: 8.4 release notes proof reading 1/2

Поиск
Список
Период
Сортировка
Искать
От
Bruce Momjian
Тема
Re: 8.4 release notes proof reading 1/2
Дата
Msg-id
200903281424.n2SEOAK05146@momjian.us
Ответ на
Список
Дерево обсуждения
Re: 8.4 release notes proof reading 1/2 Andrew Gierth <andrew@tao11.riddles.org.uk>
Re: 8.4 release notes proof reading 1/2 Bruce Momjian <bruce@momjian.us>
Re: 8.4 release notes proof reading 1/2 "David E. Wheeler" <david@kineticode.com>
Re: 8.4 release notes proof reading 1/2 Bruce Momjian <bruce@momjian.us>
David E. Wheeler wrote:
> On Mar 27, 2009, at 6:40 PM, Bruce Momjian wrote:
> 
> > Thanks, text updated:
> >
> >       While semi-joins merely replace existing IN joins, anti-joins
> >       are a new capability for NOT EXISTS clauses (Tom) This improves
> >       optimization possibilities.
> 
> I'm not enough of a relational algebra geek to really understand what  
> that means. Will there be a link or something to some documentation or  
> even, *gasp*, a blog entry explaining what this means and why it's  
> important?

Uh, not really;  the optimizer stuff is usually quite vague and Tom
might end update removing it once he goes over the release note anyway
(he has in the past).  I documented it because it is a user-visible
change,  I think, becuase it might show up in EXPLAIN.

--  Bruce Momjian          http://momjian.us EnterpriseDB                             http://enterprisedb.com
 + If your life is a hard drive, Christ can be your backup. +

В списке pgsql-hackers по дате отправления
От: Bruce Momjian
Дата:
От: Andrew Gierth
Дата:
FAQ