Joshua Berry wrote:
I couldn't find the operator '@' for intervals and found this thread from over six years ago: http://archives.postgresql.org/pgsql-general/2003-09/msg00292.php | "Claudio Lapidus" <clapidus@xxxxxxxxxxx> writes: | > Bruce Momjian wrote: | >> Why would you want an abolute value of a negative interval? | | > Because I'm trying to match pairs of records that satisfy certain criteria, | | Given that we have a unary-minus operator for intervals, I see no | conceptual objection to having an absolute-value operator (and \do shows | that interval is the only standard datatype that has the former but not | the latter). | | However, given that it doesn't seem to be a really widely useful | operator, I think this is the kind of itch that you'll have to scratch | yourself. Send us a patch and it'll get into the next release ... | | regards, tom lane Is this is the case now? I have some data that is related but requires fuzzy joining on timestamps within a time interval. I'd like to be able to do this: select * from enviados e, recibidos r where @ (e.fecha - r.fecha) < interval '1 second' rather than this: select * from enviados e, recibidos r where (e.fecha - r.fecha) < interval '1 second' AND (r.fecha - e.fecha) < interval '1 second' or this: select * from enviados e, recibidos r where (r.fecha + interval '1 seconds', r.fecha - interval '1 seconds') OVERLAPS (e.fecha, e.fecha); If such an operator doesn't exist yet, I'm keen to try to generate a patch and tests; but I could use some pointers as to which project files that should be related to such a change. Regards, -Joshua Berry
You should test for a positive or negative interval against INTERVAL '0 seconds' because you can have a positive interval that is a fraction of a second.
But we've got two projects that implement a period data type, pgTemporal and Chronos.
http://pgfoundry.org/projects/temporal/ http://pgfoundry.org/projects/timespan/ Scott Bailey -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
