In Oracle, the LPAD function returns the string left-padded to the specified number of characters. LPAD accepts 2 or 3 parameters in Oracle.
MariaDB also provides the LPAD function, and since MariaDB 10.3.1 it accepts 2 or 3 parameters, so no conversion is required.
Oracle:
-- Pad string with blanks (default) SELECT LPAD('abc', 7) FROM dual; # abc -- Pad string with * SELECT LPAD('abc', 7, '*') FROM dual; # ****abc
MariaDB:
-- Pad string with blanks (default) SELECT LPAD('abc', 7); # abc -- Pad string with * SELECT LPAD('abc', 7, '*'); # ****abc
For more information, see Oracle to MariaDB Migration.