Re: Range Types: << >> -|- ops vs empty range - Mailing list pgsql-hackers

From Kevin Grittner
Subject Re: Range Types: << >> -|- ops vs empty range
Date
Msg-id 4D552191020000250003A85F@gw.wicourts.gov
Whole thread Raw
In response to Re: Range Types: << >> -|- ops vs empty range  (Jeff Davis <pgsql@j-davis.com>)
Responses Re: Range Types: << >> -|- ops vs empty range  (Josh Berkus <josh@agliodbs.com>)
List 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


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