Re: SQL compliant interval implementation

Brendan Jurd wrote:
> On 5/24/06, Josh Berkus <josh@agliodbs.com> wrote:
> > Brendan,
> >
> > > There are two classes of intervals. One class, called year-month
> > > intervals, has an express or implied datetime precision that includes
> > > no fields other than YEAR and MONTH, though not both are required. The
> > > other class, called day-time intervals, has an express or implied
> > > interval precision that can include any fields other than YEAR or
> > > MONTH.
> >
> > Yeah, we used to do that.  It sucked.  In fact, most developers of
> > applications which were calendar-heavy ended up using custom data types to
> > work around the SQL-spec INTERVAL limitations.  And that benefits nobody.
> >
> 
> Could you elaborate on how it sucked?  Apart from the issue of
> daylight savings which Tom has mentioned, what are these limitations
> that needed to be worked around?
> 
> I've been searching through the archives for discussions relating to
> intervals, but haven't come across the one you're describing.  Most
> probably because there have been a LOT of discussions relating to
> intervals.

Well, it seems to just eliminate the 30-day problem by disallowing it,
and creating two data types.  I don't see how that is better than what
we have now.

--  Bruce Momjian   http://candle.pha.pa.us EnterpriseDB    http://www.enterprisedb.com
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