Function-based index using DESC

When using desc in create index statement, Oracle interprets this index as function-based index:

SQL> select i.TABLE_NAME, i.INDEX_NAME, i.INDEX_TYPE, e.COLUMN_EXPRESSION, C.COLUMN_NAME, C.DESCEND from dba_indexes i

join dba_ind_columns c on i.index_name=c.index_name

join dba_ind_expressions e on i.index_name=e.index_name

where i.table_owner='&owner';

  2    3    4  Enter value for owner: USER

old   4: where i.table_owner='&owner'

new   4: where i.table_owner='USER'

TABLE_NAME                     INDEX_NAME                     INDEX_TYPE

------------------------------ ------------------------------ ----------

COLUMN_EXPRESSION

--------------------------------------------------------------------------------

COLUMN_NAME

------------------------------------------------------------------------------------------------------------------------------------------------------

DESC

----

TARGET1                     IDX_ID_DESC                       FUNCTION-B

                                                              ASED NORMA

                                                              L

"ID"

SYS_NC00018$

DESC

TARGET1                     IDX_CREATED_DESC                  FUNCTION-B

                                                              ASED NORMA

                                                              L

"CREATED"

SYS_NC00019$

DESC