Alexander Farber <alexander.far...@gmail.com> writes: > Then I am trying to add a function, which would receive a series of > locations (longitude and latitude pairs in microdegrees) and return a list > of lowercase 2-letter country codes, like "de", "pl", "lv":
> CREATE OR REPLACE FUNCTION find_countries(locations BIGINT[][]) > RETURNS TABLE (country TEXT) AS $$ Postgres isn't too friendly to representing a list of locations as a 2-D array, because we generally don't treat arrays as being arrays-of-arrays, so unnest produces a set of bigints not a set of smaller arrays. You might be best advised to create a composite type like "location (long bigint, lat bigint)" and use an array of that. If you're really hot to use a 2-D array, the only construct I can think of that's on board with unnesting that the way you need is plpgsql's FOREACH SLICE syntax: https://www.postgresql.org/docs/devel/plpgsql-control-structures.html#PLPGSQL-FOREACH-ARRAY You could probably make a custom version of unnest that uses that and then keep your query about the same. regards, tom lane
