Q1. A senior DBA asked you to execute the following command to improve performance:
SQL> ALTER TABLE subscribe log STORAGE (BUFFER_POOL recycle);
You checked the data in the SUBSCRIBE_LOG table and found that it is a large table
containing one million rows.
What could be a reason for this recommendation?
A. The keep pool is not configured.
B. Automatic Workarea Management is not configured.
C. Automatic Shared Memory Management is not enabled.
D. The data blocks in the SUBSCRIBE_LOG table are rarely accessed.
E. All the queries on the SUBSCRIBE_LOG table are rewritten to a materialized view.
Answer: D
Explanation: The most of the rows in SUBSCRIBE_LOG table are accessed once a week.
Q2. Which four actions are possible during an Online Data file Move operation?
A. Creating and dropping tables in the data file being moved
B. Performing file shrink of the data file being moved
C. Querying tables in the data file being moved
D. Performing Block Media Recovery for a data block in the data file being moved
E. Flashing back the database
F. Executing DML statements on objects stored in the data file being moved
Answer: A,C,E,F
Explanation: - You can now move On line Datafile without hove to stop Monoged Recovery and manually copy and rename Files. This can even be used to move Datafiles from or to ASM.
-New in Oracle Database 12c: FROM METAUNK. Physical Standby Database is in Active Data Guard Mode (opened READ ONLY and Managed Recovery is running): It is now possible to online move a Datafile while Managed Recovery is running, ie. the Physical Standby Database is in Active Data Guard Mode. You con use this Command to move the Datafile
-A flashback operation does not relocate a moved data file to its previous location. If you move a data file online from one location to another and later flash back the database to a point in time before the move, then the Data file remains in the new location, but the contents of the Data file ore changed to the contents at the time specified in the flashback. Oracle0 Database Administrator's Guide 12c Release 1 (12.1)
Q3. Which two statements correctly describe the relationship between data files and logical database structures?
A. A segment cannot span data files.
B. A data file can belong to only one tablespace.
C. An extent cannot span data files.
D. The size of an Oracle data block in a data file should be the same as the size of an OS block.
Answer: B,C
Reference: https://mohibalvi.wordpress.com/tag/alter-tablespace/
Q4. Which three statements are true concerning the multitenant architecture?
A. Each pluggable database (PDB) has its own set of background processes.
B. A PDB can have a private temp tablespace.
C. PDBs can share the sysaux tablespace.
D. Log switches occur only at the multitenant container database (CDB) level.
E. Different PDBs can have different default block sizes.
F. PDBs share a common system tablespace.
G. Instance recovery is always performed at the CDB level.
Answer: B,D,G
Explanation: B:
* A PDB would have its SYSTEM, SYSAUX, TEMP tablespaces.It can also contains other
user created tablespaces in it.
* There is one default temporary tablespace for the entire CDB. However, you can create additional temporary tablespaces in individual PDBs.
D:
* There is a single redo log and a single control file for an entire CDB
* A log switch is the point at which the database stops writing to one redo log file and begins writing to another. Normally, a log switch occurs when the current redo log file is completely filled and writing must continue to the next redo log file.
G: instance recovery The automatic application of redo log records to uncommitted data blocks when an database instance is restarted after a failure.
Incorrect: Not A:
* There is one set of background processes shared by the root and all PDBs. –
* High consolidation density. The many pluggable databases in a single container database share its memory and background processes, letting you operate many more pluggable databases on a particular platform than you can single databases that use the old architecture.
Not C: There is a separate SYSAUX tablespace for the root and for each PDB.
Not F: There is a separate SYSTEM tablespace for the root and for each PDB. -
Q5. You are planning the creation of a new multitenant container database (CDB) and want to store the ROOT and SEED container data files in separate directories.
You plan to create the database using SQL statements.
Which three techniques can you use to achieve this?
A. Use Oracle Managed Files (OMF).
B. Specify the SEED FILE_NAME_CONVERT clause.
C. Specify the PDB_FILE_NAME_CONVERT initialization parameter.
D. Specify the DB_FILE_NAMECONVERT initialization parameter.
E. Specify all files in the CREATE DATABASE statement without using Oracle managed Files (OMF).
Answer: A,B,C
Explanation: You must specify the names and locations of the seed's files in one of the following ways:
* (A) Oracle Managed Files
* (B) The SEED FILE_NAME_CONVERT Clause
* (C) The PDB_FILE_NAME_CONVERT Initialization Parameter
Q6. Which action takes place when a file checkpoint occurs?
A. The checkpoint position is advanced in the checkpoint queue.
B. All buffers for a checkpointed file that were modified before a specific SCN are written to disk by DBWn and the SCN is stored in the control file.
C. The Database Writer process (DBWn) writes all dirty buffers in the buffer cache to data files.
D. The Log Writer process (LGWR) writes all redo entries in the log buffer to online redo log files.
Answer: C
Q7. You notice a performance change in your production Oracle 12c database. You want to know which change caused this performance difference.
Which method or feature should you use?
A. Compare Period ADDM report
B. AWR Compare Period report
C. Active Session History (ASH) report
D. Taking a new snapshot and comparing it with a preserved snapshot
Answer: B
Explanation: The awrddrpt.sql report is the Automated Workload Repository Compare
Period Report. The awrddrpt.sql script is located in the $ORACLE_HOME/rdbms/admin directory.
Incorrect:
Not A: Compare Period ADDM
Use this report to perform a high-level comparison of one workload replay to its capture or to another replay of the same capture. Only workload replays that contain at least 5 minutes of database time can be compared using this report.
Q8. Which three statements are true concerning unplugging a pluggable database (PDB)?
A. The PDB must be open in read only mode.
B. The PDB must be dosed.
C. The unplugged PDB becomes a non-CDB.
D. The unplugged PDB can be plugged into the same multitenant container database (CDB)
E. The unplugged PDB can be plugged into another CDB.
F. The PDB data files are automatically removed from disk.
Answer: B,D,E
Explanation: B, not A: The PDB must be closed before unplugging it.
D: An unplugged PDB contains data dictionary tables, and some of the columns in these encode information in an endianness-sensitive way. There is no supported way to handle the conversion of such columns automatically. This means, quite simply, that an unplugged PDB cannot be moved across an endianness difference.
E (not F): To exploit the new unplug/plug paradigm for patching the Oracle version most effectively, the source and destination CDBs should share a filesystem so that the PDB’s datafiles can remain in place.
Reference: Oracle White Paper, Oracle Multitenant
Q9. The ORCL database is configured to support shared server mode. You want to ensure that a user connecting remotely to the database instance has a one-to-one ratio between client and server processes.
Which connection method guarantees that this requirement is met?
A. connecting by using an external naming method
B. connecting by using the easy connect method
C. creating a service in the database by using the dbms_service.create_service procedure and using this service for creating a local naming service"
D. connecting by using the local naming method with the server = dedicated parameter set in the tnsnames.ora file for the net service
E. connecting by using a directory naming method
Answer: C,E
Q10. Which two partitioned table maintenance operations support asynchronous Global Index Maintenance in Oracle database 12c?
A. ALTER TABLE SPLIT PARTITION
B. ALTER TABLE MERGE PARTITION
C. ALTER TABLE TRUNCATE PARTITION
D. ALTER TABLE ADD PARTITION
E. ALTER TABLE DROP PARTITION
F. ALTER TABLE MOVE PARTITION
Answer: C,E
Explanation: Asynchronous Global Index Maintenance for DROP and TRUNCATE PARTITION This feature enables global index maintenance to be delayed and decoupled from a DROP and TRUNCATE partition without making a global index unusable. Enhancements include faster DROP and TRUNCATE partition operations and the ability to delay index maintenance to off-peak time.
Reference: Oracle Database VLDB and Partitioning Guide 12c