On Wed, Feb 20, 2019 at 12:27:26PM +0000, PG Doc comments form wrote: > The following documentation comment has been logged on the website: > > Page: https://www.postgresql.org/docs/11/functions-range.html > Description: > > Hi. > > It would be nice if next examples: > > << strictly left of int8range(1,10) << int8range(100,110) t > >> strictly right of int8range(50,60) >> int8range(20,30) t > &< does not extend to the right of int8range(1,20) &< > int8range(18,20) > t > &> does not extend to the left of int8range(7,20) &> int8range(5,10) > t > > are extended by: > **not** strictly left of, **not** strictly right of, **extends** to the > right of, **extends** to the left of > > Because without manual experiments I can not imagine the ranges that cause > 'false' result for the examples above.
Well, they are not technically negatives of each other. << means the first is all left of the second, while &< means that it doesn't go to the right of the second, e.g., SELECT int8range(1,10) &< int8range(100,110); ?column? ---------- t SELECT int8range(1,105) &< int8range(100,110); ?column? ---------- t SELECT int8range(1,200) &< int8range(100,110); ?column? ---------- f Notice it changed from true to false and none of these was strictly to the right. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + As you are, so once was I. As I am, so you will be. + + Ancient Roman grave inscription +