OCP-1Z0-052-V8.02-163题

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  

答案解析：

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 BFILElocator, 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. 

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