Which statements are true regarding SecureFile LOBs? (Choose all that apply.)
A.
The amount of undo retained is user controlled.
B.
SecureFile LOBs can be used only for nonpartitioned tables.
C.
Fragmentation is minimized by using variable-sized chunks dynamically.
D.
SecureFile encryption allows for random reads and writes of the encrypted data.
E.
It automatically detects duplicate LOB data and conserves space by storing only one
copy.
Explanation:
One of the new feature of Oracle 11g is that Oracle SecureFiles use variable chunk sizes,
which can be as large as 64 MB.By storing these chunks next to one another, Oracle also
minimizes fragmentation.
About Deduplication
SecureFiles Intelligent Deduplication, available with the Oracle Advanced Compression
Option, enables Oracle Database to automatically detect duplicate LOB data within a LOB
column or partition, and conserve space by storing only one copy of the data.
Note that you must have a license for the Oracle Advanced Compression Option before
implementing SecureFiles Intelligent Deduplication. See Oracle Database Licensing
Information for more information.
Note also that Oracle Streams does not support SecureFiles LOBs that are deduplicated.
About Encryption
SecureFiles Intelligent Encryption, available with the Oracle Advanced Security Option,
introduces a new encryption facility for LOBs. The data is encrypted using Transparent Data
Encryption (TDE), which allows the data to be stored securely, and still allows for random
read and write access.
C, D and E are correct:
https://docs.oracle.com/cd/E11882_01/appdev.112/e18294/adlob_smart.htm#ADLOB45959
C:
FRAGMENT_DELETE()
Deletes a specified fragment of the LOB
FRAGMENT_INSERT()
Inserts a fragment of data into the LOB
FRAGMENT_MOVE()
Moves a fragment of a LOB from one location in the LOB to another location
FRAGMENT_REPLACE()
Replaces a fragment of a LOB with new data
D:
About Encryption
SecureFiles Intelligent Encryption, available with the Oracle Advanced Security Option, introduces a new encryption facility for LOBs. The data is encrypted using Transparent Data Encryption (TDE), which allows the data to be stored securely, and still allows for random read and write access.
E:
DEDUPLICATE or KEEP_DUPLICATES
The DEDUPLICATE option enables SecureFiles Intelligent Deduplication; it specifies that SecureFiles LOB data that is identical in two or more rows in a LOB column, partition or subpartition must share the same data blocks. The database combines SecureFiles LOBs with identical content into a single copy, reducing storage and simplifying storage management. The opposite of this option is KEEP_DUPLICATES.