I try to convert code from other database to Postgres. CREATE TABLE test(test BOOLEAN); SELECT MAX(test) FROM test; causes error ERROR: function max(boolean) does not exist HINT: No function matches the given name and argument types. You may need to add explicit type casts. I tried SELECT MAX(test:integer)::boolean FROM test; but this casuses error ERROR: cannot cast type boolean to integer I have lot of MAX() functions applied to boolean expressions. How to force Postgres to calculate MAX(boolean) ? MAX(boolean) should return true if its argument evaluates true for at least one row. ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to majordomo@xxxxxxxxxxxxxx)