Answer: A,C,D 

Explanation: D: DB_FILE_MULTIBLOCK_READ_COUNT is one of the parameters you can use to minimize I/O during table scans. It specifies the maximum number of blocks read in one I/O operation during a sequential scan. The total number of I/Os needed to perform a full table scan depends on such factors as the size of the table, the multiblock read count, and whether parallel execution is being utilized for the operation. 

Answer: C 

Explanation: 

* The environment setup for tablespace encryption is the same as that for transparent data encryption. Before attempting to create an encrypted tablespace, a wallet must be created to hold the encryption key. 

* Setting the tablespace master encryption key is a one-time activity. This creates the master encryption key for tablespace encryption. This key is stored in an external security module (Oracle wallet) and is used to encrypt the tablespace encryption keys. 

* Before you can create an encrypted tablespace, the Oracle wallet containing the tablespace master encryption key must be open. The wallet must also be open before you can access data in an encrypted tablespace. 

* Salt is a way to strengthen the security of encrypted data. It is a random string added to the data before it is encrypted, causing repetition of text in the clear to appear different when encrypted. Salt removes the one common method attackers use to steal data, namely, matching patterns of encrypted text. 

* ALT | NO SALT By default the database appends a random string, called "salt," to the clear text of the column before encrypting it. This default behavior imposes some limitations on encrypted columns: / If you specify SALT during column encryption, then the database does not compress the data in the encrypted column even if you specify table compression for the table. However, the database does compress data in unencrypted columns and encrypted columns without the SALT parameter. 

Answer: D Explanation: 

Note: 

* Generating a Pluggable Database Manifest File for the Non-CDB 

Execute the dbms_pdb.describe procedure to generate the manifest file. 

exec dbms_pdb.describe(pdb_descr_file=>'/u01/app/oracle/oradata/noncdb/noncdb.xml'); 

Shut down the noncdb instance to prepare to copy the data files in the next section. 

shutdown immediate exit 

Answer: A,C 

Explanation: A: PGA itself is subdivided. The UGA (User Global Area) contains session state information, including stuff like package-level variables, cursor state, etc. Note that, with shared server, the UGA is in the SGA. It has to be, because shared server means that the session state needs to be accessible to all server processes, as any one of them could be assigned a particular session. However, with dedicated server (which likely what you're using), the UGA is allocated in the PGA. 

C: The Location of a private SQL area depends on the type of connection established for a session. If a session is connected through a dedicated server, private SQL areas are located in the server process’ PGA. However, if a session is connected through a shared server, part of the private SQL area is kept in the SGA. 

Note: 

* System global area (SGA) The SGA is a group of shared memory structures, known as SGA components, that contain data and control information for one Oracle Database instance. The SGA is shared by all server and background processes. Examples of data stored in the SGA include cached data blocks and shared SQL areas. 

* Program global area (PGA) 

A PGA is a memory region that contains data and control information for a server process. It is nonshared memory created by Oracle Database when a server process is started. Access to the PGA is exclusive to the server process. There is one PGA for each server process. Background processes also allocate their own PGAs. The total memory used by all individual PGAs is known as the total instance PGA memory, and the collection of individual PGAs is referred to as the total instance PGA, or just instance PGA. You use database initialization parameters to set the size of the instance PGA, not individual PGAs. 

Reference: Oracle Database Concepts 12c 

Answer: B 

Explanation: The listener is used when the connection is established. The immediate impact of stopping the listener will be that no new session can be established from a remote host. Existing sessions are not compromised. 

Answer: A,B,E 

Explanation: A: Starting with 12c, Oracle has unified all of the auditing types into one single unit called Unified auditing. You don’t have to turn on or off all of the different auidting types individually and as a matter of fact auditing is enabled by default right out of the box. The AUD$ and FGA$ tables have been replaced with one single audit trail table. All of the audit data is now stored in Secure Files table thus improving the overall management aspects of audit data itself. 

B: Further the audit data can also be buffered solving most of the common performance related problems seen on busy environments. 

E: Unified Auditing is able to collect audit data for Fine Grained Audit, RMAN, Data Pump, Label Security, Database Vault and Real Application Security operations. 

Note: 

* Benefits of the Unified Audit Trail 

The benefits of a unified audit trail are many: / (B) Overall auditing performance is greatly improved. The default mode that unified audit works is Queued Write mode. In this mode, the audit records are batched in SGA queue and is persisted in a periodic way. Because the audit records are written to SGA queue, there is a significant performance improvement. 

/ The unified auditing functionality is always enabled and does not depend on the initialization parameters that were used in previous releases 

/ (A) The audit records, including records from the SYS audit trail, for all the audited components of your Oracle Database installation are placed in one location and in one format, rather than your having to look in different places to find audit trails in varying formats. This consolidated view enables auditors to co-relate audit information from different components. For example, if an error occurred during an INSERT statement, standard auditing can indicate the error number and the SQL that was executed. Oracle Database Vault-specific information can indicate whether this error happened because of a command rule violation or realm violation. Note that there will be two audit records with a distinct AUDIT_TYPE. With this unification in place, SYS audit records appear with AUDIT_TYPE set to Standard Audit. 

/ The management and security of the audit trail is also improved by having it in single audit trail. 

/ You can create named audit policies that enable you to audit the supported components listed at the beginning of this section, as well as SYS administrative users. Furthermore, you can build conditions and exclusions into your policies. 

* Oracle Database 12c Unified Auditing enables selective and effective auditing inside the Oracle database using policies and conditions. The new policy based syntax simplifies management of auditing within the database and provides the ability to accelerate auditing based on conditions. 

* The new architecture unifies the existing audit trails into a single audit trail, enabling simplified management and increasing the security of audit data generated by the database. 

Answer: C 

Answer: A,C,D 

Explanation: A: You can create and rebuild indexes online. Therefore, you can update base tables at the same time you are building or rebuilding indexes on that table. You can perform DML operations while the index build is taking place, but DDL operations are not allowed. Parallel execution is not supported when creating or rebuilding an index online. 

D: Moving (Rebuilding) Index-Organized Tables Because index-organized tables are primarily stored in a B-tree index, you can encounter fragmentation as a consequence of incremental updates. However, you can use the ALTER TABLE...MOVE statement to rebuild the index and reduce this fragmentation. 

C: If a table can be compressed in the new tablespace, also it can be compressed in the same tablespace. 

Incorrect: 

Not B, not E: Local and Global indexes can be automatically rebuild with UPDATE 

INDEXES when you move the table. 

Answer: A,D 

Explanation: A: ASM_POWER_LIMIT specifies the maximum power on an Automatic Storage Management instance for disk rebalancing. The higher the limit, the faster rebalancing will complete. Lower values will take longer, but consume fewer processing and I/O resources. 

D: 

* Normally a separate process is fired up to do that rebalance. This will take a certain amount of time. If you want it to happen faster, fire up more processes. You tell ASM it can add more processes by increasing the rebalance power. 

* ASMB 

ASM Background Process Communicates with the ASM instance, managing storage and providing statistics 

Incorrect: Not B: A higher, not a lower, value of DISK_REPAIR_TIME would be helpful here. Not E: If you implement database writer I/O slaves by setting the DBWR_IO_SLAVES parameter, you configure a single (master) DBWR process that has slave processes that are subservient to it. In addition, I/O slaves can be used to "simulate" asynchronous I/O on platforms that do not support asynchronous I/O or implement it inefficiently. Database I/O slaves provide non-blocking, asynchronous requests to simulate asynchronous I/O.