SELECT a < (SELECT 'foo'::text COLLATE "en_GB.utf8") FROM test_col;
SQL Error: ERROR: could not determine which collation to use for string comparison
HINT: Use the COLLATE clause to set the collation explicitly.
Note, I had to include the cast to text in order for the query to execute...
David J.
On postgres built off of master on my mac (sierra), the following is the output:
DROP TABLE IF EXISTS test_col_mac; DROP TABLE CREATE TABLE test_col_mac ( a text COLLATE "de_DE", b text COLLATE "es_ES" ); CREATE TABLE INSERT INTO test_col_mac VALUES('A','A'); INSERT 0 1 SELECT a < (SELECT 'foo'::TEXT COLLATE "fr_FR") FROM test_col_mac; ?column? ---------- t (1 row)