Hi, all:
when I execute simple sql,report ERROR:
postgres=# CREATE TABLE test_v(id int,name varchar(30));
CREATE TABLE
postgres=# insert into test_v values(9,'abc'),(9,'def'),(9,'gh'), (9,'gh');
INSERT 0 4
postgres=# explain (costs off) select distinct (id,name,'D3Q84xpymM',123,'123') from test_v;
QUERY PLAN
-------------------------------------------------------------
Unique
-> Sort
Sort Key: (ROW(id, name, 'D3Q84xpymM', 123, '123'))
-> Seq Scan on test_v
(4 rows)
postgres=# select distinct (id,name,'D3Q84xpymM',123,'123') from test_v;
ERROR: could not identify a comparison function for type unknown
PostgreSQL could not identify 'D3Q84xpymM' and '123' datatype:
we can allow an UNKNOWN type to change it to TEXT,
please check my patch.
Thanks!