On 5/8/18 09:19, Chapman Flack wrote: > On 05/08/2018 08:57 AM, Ildar Musin wrote: >> >> select map (pow(2, x) - 1 for x in array[1,2,3,4,5]); > > I wonder how efficient an implementation would be possible strictly > as a function, without grammar changes?
Yeah, you can pass a function to another function (using regprocedure or just oid), so this should be possible entirely in user space. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
