Re: Help on indexing timestamps

Andre Schubert <andre@km3.de> writes:
> Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Update to 7.3, and that problem will go away.
>> 
> What is the difference between 7.2 and 7.3 related to my problem ?

7.3 is willing to index comparisons to now(), that's what ;-)

You may care to study the difference between cachable/noncachable
functions in 7.2, versus the difference between
immutable/stable/volatile functions in 7.3.  7.2 has to treat now()
as noncachable and therefore unsafe to index.  7.3 treats it as
stable and therefore safe to index.

You can work around this in 7.2 by cheating with subselects or wrapper
functions, but that's a poor substitute for a real solution.
        regards, tom lane