Re: Range Types - typo + NULL string constructor
От | Thom Brown |
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Тема | Re: Range Types - typo + NULL string constructor |
Дата | |
Msg-id | CAA-aLv6uwBh0unkE10U=oG6ZHCvR087AxWMM12dFPV8ud-z_Jw@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: Range Types - typo + NULL string constructor (Florian Pflug <fgp@phlo.org>) |
Список | pgsql-hackers |
On 11 October 2011 02:14, Florian Pflug <fgp@phlo.org> wrote: > On Oct10, 2011, at 20:06 , Thom Brown wrote: >> Okay, a real example of why discrete should be '[]' and continuous >> should be '[)'. >> >> If you book a meeting from 09:00 to 11:00 (tsrange), at 11:00 >> precisely it either becomes free or is available to someone else, so >> it can be booked 11:00 to 12:00 without conflict. >> >> If you have raffle tickets numbered 1 to 100 (int4range), and you ask >> for tickets 9 to 11, no-one else can use 11 as it aligns with the last >> one you bought. >> >> So for me, it's intuitive for them to behave differently. So yes, >> default behaviour would vary between types, but I didn't previously >> read anything on default_flags, so I don't know where that comes into >> it. Shouldn't it be the case that if a type has a canonical function, >> it's entirely inclusive, otherwise it's upper boundary is exclusive? > > First, there's the type "date", which in my book is discrete. So we'd make > date ranges closed by default, not half-open. And there's timestamp, which > is continuous so we'd make its default half-open. That doesn't seem exactly > intuitive to me. Ah yes, I agree there. Okay, I see your point. -- Thom Brown Twitter: @darkixion IRC (freenode): dark_ixion Registered Linux user: #516935 EnterpriseDB UK: http://www.enterprisedb.com The Enterprise PostgreSQL Company
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