Daniele Varrazzo wrote:
> Hello,
>
> =# select extract(epoch from 'infinity'::timestamp);
> date_part
> -----------
> 0
>
> A better value would be 'infinity'::float8. Ditto for -infinity.
>
> I'm trying to use a box-based index to represent the intervals in a
> table containing a pair of fields date_from, date_to (timestamps),
> where semi-open intervals are represented with +/- infinity. Building
> the boxes using extract(epoch from ...) creates wrong entries as
> semi-open intervals are converted into a box with a corner in (0,0).
Looking at:
timestamptz_part(PG_FUNCTION_ARGS)
I see:
if (TIMESTAMP_NOT_FINITE(timestamp)) { result = 0; PG_RETURN_FLOAT8(result); }
The assumption is that extracting _anything_ from an infinite timestamp
should be zero, but I can see your point that epoch perhaps should be
special-cased to return +/- inifinity.
Does anyone object to changing this?
-- Bruce Momjian <bruce@momjian.us> http://momjian.us EnterpriseDB
http://enterprisedb.com
+ It's impossible for everything to be true. +
