Forgive my ignorance, but I don't entirely understand the problem. What does '+' and '-' refer to exactly? Thanks!
On Fri, Jun 21, 2013 at 4:35 AM, Hitoshi Harada <umi.tan...@gmail.com>wrote: > > > > On Fri, Jun 21, 2013 at 3:20 AM, Craig Ringer <cr...@2ndquadrant.com>wrote: > >> On 06/21/2013 05:32 PM, Hitoshi Harada wrote: >> >> > I also later found that we are missing not only notion of '+' or '-', >> > but also notion of 'zero value' in our catalog. Per spec, RANGE BETWEEN >> > needs to detect ERROR if the offset value is negative, but it is not >> > always easy if you think about interval, numeric types as opposed to >> > int64 used in ROWS BETWEEN. >> >> Zero can be tested for with `val = (@ val)` ie `val = abs(val)`. That >> should make sense for any type in which the concept of zero makes sense. >> >> >> Yeah, I mean, it needs to know if offset is negative or not by testing > with zero. So we need "zero value" or "is_negative function" for each type. > > Thanks, > -- > Hitoshi Harada >
