ORA-03050
invalid identifier: string is a reserved word
Cause
A reserved word was used when an identifier or column name was expected.
Action
Enter a valid identifier or column name. A valid identifier must begin with a letter, be less than or equal to 128 characters, and consist of only alphanumeric characters and the special characters $, _, and #. If it contains other characters, then it must be enclosed in double quotation marks. It must not be a reserved word, unless it is enclosed in double quotation marks.