ltrim removes characters from the left of char, with all the leftmost characters that appear in set removed; set defaults to a single blank. If char is a character literal, then you must enclose it in single quotes. Oracle begins scanning char from its first character and removes all characters that appear in set until reaching a character not in set and then returns the result.

Both char and set can be any of the datatypes CHAR, VARCHAR2, NCHAR, NVARCHAR2, CLOB, or NCLOB. The string returned is of VARCHAR2 datatype and is in the same character set as char.