Re: Array: comparing first N elements?

Hello

create or replace function eqn(anyarray, anyarray, int)
returns boolean as $$
 select not exists(select $1[i] from generate_series(1,$3) g(i)
                          except
                          select $2[i] from generate_series(1,$3) g(i))
$$ language sql immutable strict;

postgres=# select eqn(array[1,2,3,4,5], array[1,2,3,5,6], 3);
 eqn
-----
 t
(1 row)

Time: 1,590 ms
postgres=# select eqn(array[1,2,3,4,5], array[1,2,3,5,6], 4);
 eqn
-----
 f
(1 row)