Supported Data Types

You may encounter the following situations when you use external tables to move data between databases:

The database character set and the database national character set may be different between the two platforms.
The endianness of the platforms for the two databases may be different.

The ORACLE_DATAPUMP access driver automatically resolves some of these situations.

The following data types are automatically converted during loads and unloads:

Character (CHAR, NCHAR, VARCHAR2, NVARCHAR2)
RAW
NUMBER
Date/Time
BLOB
CLOB and NCLOB
ROWID and UROWID

If you attempt to use a data type that is not supported for external tables, then you receive an error. This is demonstrated in the following example, in which the unsupported data type, LONG, is used:

SQL> CREATE TABLE bad_datatype_xt
  2  (
  3    product_id             NUMBER(6),
  4    language_id            VARCHAR2(3),
  5    translated_name        NVARCHAR2(50),
  6    translated_description LONG
  7  )
  8  ORGANIZATION EXTERNAL
  9  (
 10    TYPE ORACLE_DATAPUMP
 11    DEFAULT DIRECTORY def_dir1
 12    LOCATION ('proddesc.dmp')
 13  );
  translated_description LONG
  *
ERROR at line 6:
ORA-30656: column type not supported on external organized table