Explanation
HCC requires the use of Oracle Storage - Exadata (A), Pillar Axiom (G) or Sun ZFS Storage Appliance (ZFSSA).
Note:
* Hybrid Columnar Compression, initially only available on Exadata, has been extended to support Pillar Axiom and Sun ZFS Storage Appliance (ZFSSA) storage when used with Oracle Database Enterprise Edition
11.2.0.3 and above
* Oracle offers the ability to manage NFS using a feature called Oracle Direct NFS (dNFS). Oracle Direct NFS implements NFS V3 protocol within the Oracle database kernel itself. Oracle Direct NFS client overcomes many of the challenges associated with using NFS with the Oracle Database with simple configuration, better performance than traditional NFS clients, and offers consistent configuration across platforms.

Explanation/Reference:
Explanation:
C: Commonly granted privileges that have been made to the common role apply in the root and all PDBs
to which the grantor can connect, including PDBs that may be added later on.
D: Common users can both create and grant common roles to other common and local users.
E: Local users cannot create common roles.
Note: A common role is a role that is created in the root; a local role is created in a PDB.
Incorrect Answers:
A: Local users can grant common roles to common and other local users.
References: https://docs.oracle.com/database/121/DBSEG/authorization.htm

Explanation
Step 1 (2). Seed column usage
Oracle must observe a representative workload, in order to determine the appropriate column groups. Using the new procedure DBMS_STATS.SEED_COL_USAGE, you tell Oracle how long it should observe the workload.
Step 2: (3) You don't need to execute all of the queries in your work during this window. You can simply run explain plan for some of your longer running queries to ensure column group information is recorded for these queries.
Step 3. (1) Create the column groups
At this point you can get Oracle to automatically create the column groups for each of the tables based on the usage information captured during the monitoring window. You simply have to call the DBMS_STATS.CREATE_EXTENDED_STATS function for each table.This function requires just two arguments, the schema name and the table name. From then on, statistics will be maintained for each column group whenever statistics are gathered on the table.
Note:
* DBMS_STATS.REPORT_COL_USAGE reports column usage information and records all the SQL operations the database has processed for a given object.
* The Oracle SQL optimizer has always been ignorant of the implied relationships between data columns within the same table. While the optimizer has traditionally analyzed the distribution of values within a column, he does not collect value-based relationships between columns.
* Creating extended statistics
Here are the steps to create extended statistics for related table columns withdbms_stats.created_extended_stats:
1 - The first step is to create column histograms for the related columns.
2 - Next, we run dbms_stats.create_extended_stats to relate the columns together.
Unlike a traditional procedure that is invoked via an execute ("exec") statement, Oracle extended statistics are created via a select statement.