Cause: In the INDEX BY clause of a
PL/SQL table declaration, a datatype other than BINARY_INTEGER, PLS_INTEGER,
or VARCHAR2 was specified. PL/SQL tables can have one column and a primary
key. The column can have any scalar type, but the primary key must be either a
binary integer type or VARCHAR2.
Action: Use one of the supported key
types in the INDEX BY clause.

Relared Errors:
PLS-00316:
PL/SQL TABLEs must use a single index
PLS-00317:
incomplete type string was not completed in its declarative
region
PLS-00318: type
string is malformed because it is a non-REF mutually recursive
type
PLS-00319:
subquery in an IN or NOT IN clause must contain exactly one
column
PLS-00320: the
declaration of the type of this expression is incomplete or
malformed
PLS-00321:
expression `string` is inappropriate as the left hand side of an
assignmen
PLS-00322:
declaration of a constant `string` must contain an initialization
assignme
PLS-00323:
subprogram or cursor `string` is declared in a package specification
and m
PLS-00324:
cursor attribute may not be applied to non-cursor
`string`
PLS-00325:
non-integral numeric literal string is inappropriate in this
context