"Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> "Matthias" <matthias.cesna@gmail.com> wrote:
>> It is about when using a upper-boundary timestamp. The value of
>> 9999-12-31 23:59:59.999999 is sometimes used to indicate an infinite
>> validity.
> One other thought -- using a "magic value" for something like this is
> usually a bad idea. NULL indicates the absence of a value, and means
> "unknown or not applicable". I generally use that for an upper bound
> when there is no valid upper bound.
Also, if you really want to convey the idea of "infinity" rather than
"unknown", the timestamp types do have special values 'infinity'
and '-infinity', which are likewise far preferable to choosing magic
regular values.
regards, tom lane