Re: Efficient date range search?
From: Jonathan Leffler <jleffler_at_earthlink.net>
Date: Wed, 09 Oct 2002 05:00:52 GMT
Message-ID: <3DA3B7D8.30407_at_earthlink.net>
>
> why not
> TIMESTAMP '2001-07-04 19:30:00' BETWEEN born AND died
Date: Wed, 09 Oct 2002 05:00:52 GMT
Message-ID: <3DA3B7D8.30407_at_earthlink.net>
Dieter Nöth wrote:
>>Then the criterion for 'alive at time 2001-07-04 19:30:00' is: >> >>WHERE born <= TIMESTAMP '2001-07-04 19:30:00' >> AND died >= TIMESTAMP '2001-07-04 19:30:00'
>
> why not
> TIMESTAMP '2001-07-04 19:30:00' BETWEEN born AND died
No reason except I've never looked at it that way round; I'm used to thinking of "variable BETWEEN constant1 AND constant2" - inertia, in other words. I doubt if it makes any difference whatsoever to the execution plan which of the two is written.
-- Jonathan Leffler #include <disclaimer.h> Email: jleffler_at_earthlink.net, jleffler_at_us.ibm.com Guardian of DBD::Informix 1.00.PC2 -- http://dbi.perl.org/Received on Wed Oct 09 2002 - 07:00:52 CEST