Introduction to Oracle BFILE Data Type

Oracle BFILE data type is a special data type in the Oracle database used for handling binary file data. Unlike BLOB and CLOB types, BFILE data type does not store the binary file itself, but stores the address (file system path) of the file. Therefore, it is suitable for storing large binary files such as images, audios, videos, etc., to reduce the storage burden on the database server. When using BFILE data type, it is required to create the file in the file system of the operating system.

Syntax

In Oracle, the following syntax can be used to create a column of BFILE data type:

column_name BFILE

where column_name is the name of the column to be created.

Use Cases

BFILE data type is suitable for storing large binary files such as images, audios, videos, etc. Since it does not store the binary data itself but the file address, it can significantly reduce the storage burden on the database server. Additionally, BFILE data type can also be used for storing office documents such as documents and spreadsheets.

Examples

Here are two examples of using BFILE data type.

Example 1: Creating a table with BFILE data type

First, create an image file named sample_image.jpg in the file system. Then, create a table named image_table in Oracle with a column of BFILE data type to store the address of the image file.

CREATE TABLE image_table (
   image_file BFILE
);

Now, data can be inserted into image_table as follows:

INSERT INTO image_table VALUES (BFILENAME('IMAGE_DIR', 'sample_image.jpg'));

where IMAGE_DIR is the directory name containing the sample_image.jpg file.

Example 2: Querying a table with BFILE data type

The following SQL statement can be used to query the data in the image_table table:

SELECT image_file FROM image_table;

This will return a result set containing BFILE data type. To access the file, FILEOPEN and GETLENGTH functions in the DBMS_LOB package provided by Oracle can be used. Here is an example:

DECLARE
   file_handle BFILE;
   file_length NUMBER;
BEGIN
   SELECT image_file INTO file_handle FROM image_table;
   file_length := DBMS_LOB.GETLENGTH(file_handle);
   DBMS_LOB.FILEOPEN(file_handle);
   DBMS_OUTPUT.PUT_LINE('File length: ' || file_length);
   DBMS_LOB.FILECLOSE(file_handle);
END;

Conclusion

Oracle BFILE data type is a useful data type for storing the address of large binary files. It is suitable for storing images, audios, videos, and other large files, which can effectively reduce the storage burden on the database server and improve the performance of the database system. When using BFILE data type, it is important to ensure that the file exists and is accessible in the file system of the operating system. In summary, Oracle BFILE data type is a valuable data type that can be used for storing large binary file addresses, providing benefits in terms of storage efficiency and database performance.