Difference between revisions of "Oracle Secure Files"
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== Benefits of the SecureFiles == | == Benefits of the SecureFiles == | ||
− | + | - Variable chunk size | |
− | + | - De-duplication | |
** Oracle stores only reference if identical copy of LOB data is already in database. Oracle uses a secure hash index to detect duplication. | ** Oracle stores only reference if identical copy of LOB data is already in database. Oracle uses a secure hash index to detect duplication. | ||
<pre> | <pre> |
Revision as of 19:32, 14 March 2011
What is SecureFiles?
- Current solutions before 11g to store unstructured or semi-structured data
- LOB – part of database but there is a limitation in sizing, low concurrency of DMLs
- OS Files – ease of access, compressed format, but not part of db backup nor security
- The SecureFiles in 11g gives the best features of database-resident LOBs and OS files.
- Note that traditional LOBs are still available in the form of BasicFiles.
Benefits of the SecureFiles
- Variable chunk size
- De-duplication
- Oracle stores only reference if identical copy of LOB data is already in database. Oracle uses a secure hash index to detect duplication.
alter table contracts_sec modify lob(orig_file)(DEDUPLICATE LOB);
- Main benefit is dramatic reduction in storage usage.
- Compression
- Oracle stores only reference if identical copy of LOB data is already in database.
alter table contracts_sec modify lob(orig_file)(COMPRESS HIGH);
- Uncompress only the required set of data blocks for random read and write access
- Default compression is MEDIUM.
- Advanced Compression Option License is required
- Encryption
- Supports the industry-standard encryption algorithms: 3DES168, AES128, AES192 (default), and AES256.
alter table contracts_sec modify lob(orig_file)(ENCRYPT USING 'AES128');
- Advanced Compression Option License is required.
Enabling Oracle SecureFiles
- Tablespace used must be Automatic Segment Space Management (ASSM) enabled – default setting in 11g.
- Using the DB_SECUREFILE init parameter which can have the following values
- ALWAYS – Attempts to create all LOBs as SecureFile, but as BasicFile only on non-ASSM enabled tablespace
- FORCE – Forces all LOBs created going forward to be SecureFile LOBs
- PERMITTED – Allows SecureFile to be created (default)
- NEVER – Disallows SecureFile from being created going forward
- IGNORE – Disallows SecureFile and ignore any errors