Re: Range Types: << >> -|- ops vs empty range

Поиск
Список
Период
Сортировка
От Kevin Grittner
Тема Re: Range Types: << >> -|- ops vs empty range
Дата
Msg-id 4D552191020000250003A85F@gw.wicourts.gov
обсуждение исходный текст
Ответ на Re: Range Types: << >> -|- ops vs empty range  (Jeff Davis <pgsql@j-davis.com>)
Ответы Re: Range Types: << >> -|- ops vs empty range  (Josh Berkus <josh@agliodbs.com>)
Список pgsql-hackers
Jeff Davis <pgsql@j-davis.com> wrote:
> ">>" means "strictly right of"
> "<<" means "strictly left of"
> "-|-" means "adjacent" (touching but not overlapping)
> 
> I'm open to suggestion about how those behave with empty ranges.
OK, that still leaves a lot to the imagination, though.  To try to
clarify in *my* mind:
"empty range"
=============
Zero length? If so, is it fixed at some point, but empty?   '(x,x)'?   '[x,x)'?
Is it everything? '[-inf,+inf]'?
Is it really meaningfully distinct from NULL?
Where do you see it being useful?
-Kevin


В списке pgsql-hackers по дате отправления:

Предыдущее
От: Alex Hunsaker
Дата:
Сообщение: Re: Careful PL/Perl Release Not Required
Следующее
От: Greg Smith
Дата:
Сообщение: Re: Debian readline/libedit breakage