OCP 1Z0 052 163

163. You want to access employee details contained in flat files as part of the EMPLOYEE table. You plan

to add a new column to the EMPLOYEE table to achieve this.

Which data type would you use for the new column?

A.CLOB

B.BLOB

C.BFILE

D.LONG RAW

Answer: C

访问 flat files中的数据，只有用外部表 bfile data type

http://docs.oracle.com/cd/E11882_01/server.112/e41084/sql_elements001.htm#SQLRF50996

BFILE Data Type

The

BFILE

data type enables access to binary file LOBs that are stored in file systems outside Oracle Database. A

BFILE

column or attribute stores a

BFILE

locator,
which serves as a pointer to a binary file on the server file system. The locator maintains the directory name and the filename.

You can change the filename and path of a

BFILE

without affecting the base table by using the

BFILENAME

function. Refer toBFILENAME for
more information on this built-in SQL function.

Binary file LOBs do not participate in transactions and are not recoverable. Rather, the underlying operating system provides file integrity and durability.

BFILE

data can be up to 264-1 bytes,
although your operating system may impose restrictions on this maximum.

The database administrator must ensure that the external file exists and that Oracle processes have operating system read permissions on the file.

The

BFILE

data type enables read-only support of large binary files. You cannot modify or replicate such a file. Oracle provides APIs to access file data. The primary interfaces that you use to access file data are the

DBMS_LOB

package
and Oracle Call Interface (OCI).