Re: tstzrange with ... 'infinity'] + upper_inf() using 9.2.4 - Mailing list pgsql-general

From Ralph Graulich
Subject Re: tstzrange with ... 'infinity'] + upper_inf() using 9.2.4
Date
Msg-id A9103D7E-4B8E-41C3-A009-081C0762B74D@shauny.de
Whole thread Raw
In response to Re: tstzrange with ... 'infinity'] + upper_inf() using 9.2.4  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
> No, that's the point of the sentence about the range mechanisms not
> understanding special values of the underlying type.  upper_inf tests
> for a range with no upper bound, period.  It would need some
> type-specific special knowledge to do what you're hoping for, and it
> has not got that.

Got that, thanks Tom!

So I can simply use

select tstzrange('2013-05-01'::timestamp, 'infinity'::timestamp, '[]') @> 'infinity'::timestamptz as validity;
 validity
----------
 t
(1 row)

to test for the case where the upper bound is given (= not null) and infinite.

And when one formerly used two timestamptz fields (valid_from, valid_until) to simulate the range type before the range
typewas implemented and checked for 

WHERE valid_until IS NULL

that's where we now use the "upper_inf()" function.

Regards
Ralph



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