Oracle Oracle Certifications 1Z0-060 Questions & Answers

• Question 101:

  A warehouse fact table in your Oracle 12c Database is range-partitioned by month and accessed frequently with queries that span multiple partitions The table has a local prefixed, range partitioned index.

  Some of these queries access very few rows in some partitions and all the rows in other partitions, but these queries still perform a full scan for all accessed partitions.

  This commonly occurs when the range of dates begins at the end of a month or ends close to the start of a month.

  You want an execution plan to be generated that uses indexed access when only a few rows are accessed from a segment, while still allowing full scans for segments where many rows are returned.

  Which three methods could transparently help to achieve this result?

  A. Using a partial local Index on the warehouse fact table month column with indexing disabled to the table partitions that return most of their rows to the queries.

  B. Using a partial local Index on the warehouse fact table month column with indexing disabled for the table partitions that return a few rows to the queries.

  C. Using a partitioned view that does a UNION ALL query on the partitions of the warehouse fact table, which retains the existing local partitioned column.

  D. Converting the partitioned table to a partitioned view that does a UNION ALL query on the monthly tables, which retains the existing local partitioned column.

  E. Using a partial global index on the warehouse fact table month column with indexing disabling for the table partitions that return most of their rows to the queries.

  F. Using a partial global index on the warehouse fact table month column with indexing disabled for the table partitions that return a few rows to the queries.

  Correct Answer: ACE

• Question 102:

  You use the segment advisor to help determine objects for which space may be reclaimed.

  Which three statements are true about the advice given by the segment advisor? (Choose three.)

  A. It may advise the use of online table redefinition for tables in dictionary-managed tablespaces.

  B. It may advise the use of segment shrink for tables in dictionary-managed tablespaces it the no chained rows.

  C. It may advise the use of online table redefinition for tables in locally managed tablespaces.

  D. It will detect and advise about chained rows.

  E. It may advise the use of segment shrink for freelist managed tables.

  Correct Answer: ACD

  http://docs.oracle.com/cd/B19306_01/server.102/b14231/schema.htm#CBBBIADA

• Question 103:

  You have altered a non-unique index to be invisible to determine if queries execute within an acceptable response time without using this index.

  Which two are possible if table updates are performed which affect the invisible index columns? (Choose two.)

  A. The index remains invisible.

  B. The index is not updated by the DML statements on the indexed table.

  C. The index automatically becomes visible in order to have it updated by DML on the table.

  D. The index becomes unusable but the table is updated by the DML.

  E. The index is updated by the DML on the table.

  Correct Answer: AE

  Unlike unusable indexes, an invisible index is maintained during DML statements.

  Note:

  * Oracle 11g allows indexes to be marked as invisible. Invisible indexes are maintained like any other index, but they are ignored by the optimizer unless the OPTIMIZER_USE_INVISIBLE_INDEXES parameter is set to TRUE at the instance or session level. Indexes can be created as invisible by using the INVISIBLE keyword, and their visibility can be toggled using the ALTER INDEX command.

• Question 104:

  What is the result of executing a TRUNCATE TABLE command on a table, in a non-CDB database, that has Flashback Archiving enabled?

  A. It fails with the ORA-665610 Invalid DDL statement on history-tracked message

  B. The rows in the table and the archive are truncated, and flashback archiving is disabled.

  C. The rows in the table are truncated without being archived.

  D. The rows in the table are archived, and then truncated.

  E. The rows in both the table and the archive are truncated.

  Correct Answer: D

  http://surachartopun.com/2010/06/ddl-on-tables-enabled-for-flashback.html

• Question 105:

  Which three activities are supported by the Data Recovery Advisor? (Choose three.)

  A. Advising on block checksum failures

  B. Advising on inaccessible control files

  C. Advising on inaccessible block change tracking files

  D. Advising on empty password files

  E. Advising on invalid block header field values

  Correct Answer: ABE

  * Data Recovery Advisor can diagnose failures such as the following:

  / (B) Components such as datafiles and control files that are not accessible because they do not exist, do not have the correct access permissions, have been taken offline, and so on

  / (A, E) Physical corruptions such as block checksum failures and invalid block header field values

  / Inconsistencies such as a datafile that is older than other database files

  / I/O failures such as hardware errors, operating system driver failures, and exceeding operating system resource limits (for example, the number of open files)

  * The Data Recovery Advisor automatically diagnoses corruption or loss of persistent data on disk, determines the appropriate repair options, and executes repairs at the user's request. This reduces the complexity of recovery process, thereby reducing the Mean Time To Recover (MTTR).

• Question 106:

  You create a table with the PERIOD FOR clause to enable the use of the Temporal Validity feature of Oracle Database 12c.

  Examine the table definition: Which three statements are true concerning the use of the Valid Time Temporal feature for the EMPLOYEES table?

  

  A. The valid time columns employee_time_start and employee_time_end are automatically created.

  B. The same statement may filter on both transaction time and valid temporal time by using the AS OF TIMESTAMP and PERIOD FOR clauses.

  C. The valid time columns are not populated by the Oracle Server automatically.

  D. The valid time columns are visible by default when the table is described.

  E. Setting the session valid time using DBMS_FLASHBACK_ARCHIVE.ENABLE_AT_VALID_TIME sets the visibility for data manipulation language (DML), data definition language (DDL), and queries performed by the session.

  Correct Answer: ABE

  A: To implement Temporal Validity(TV), 12c offers the option to have two date columns in that table which

  is having TV enabled using the new clause Period For in the Create Table for the newly created tables or

  in the Alter Table for the existing ones. The columns that are used can be defined while creating the table

  itself and will be used in the Period For clause or you can skip having them in the table's definition in the

  case of which, the Period For clause would be creating them internally.

  E: ENABLE_AT_VALID_TIME Procedure

  This procedure enables session level valid time flashback.

• Question 107:

  Which three statements are true regarding the use of the Database Migration Assistant for Unicode (DMU)? (Choose three.)

  A. A DBA can check specific tables with the DMU

  B. The database to be migrated must be opened read-only.

  C. The release of the database to be converted can be any release since 9.2.0.8.

  D. The DMU can report columns that are too long in the converted characterset.

  E. The DMU can report columns that are not represented in the converted characterset.

  Correct Answer: ADE

  A: In certain situations, you may want to exclude selected columns or tables from scanning or conversion

  steps of the migration process.

  D: Exceed column limit

  The cell data will not fit into a column after conversion.

  E: Need conversion

  The cell data needs to be converted, because its binary representation in the target character set is

  different than the representation in the current character set, but neither length limit issues nor invalid

  representation issues have been found.

  * Oracle Database Migration Assistant for Unicode (DMU) is a unique next-generation migration tool

  providing an end-to-end solution for migrating your databases from legacy encodings to Unicode.

  Incorrect Answers:

  C: The release of Oracle Database must be 10.2.0.4, 10.2.0.5, 11.1.0.7, 11.2.0.1, or later.

• Question 108:

  Oracle Grid Infrastructure for a stand-alone server is installed on your production host before installing the Oracle Database server. The database and listener are configured by using Oracle Restart.

  Examine the following command and its output:

  

  What does this imply?

  A. When you start an instance on a host with SQL *Plus, dependent listeners and ASM disk groups are automatically started.

  B. When a database instance is started by using the SRVCTL utility and listener startup fails, the instance is still started.

  C. When a database is created by using SQL* Plus, it is automatically added to the Oracle Restart configuration.

  D. When you create a database service by modifying the SERVICE_NAMES initialization parameter, it is automatically added to the Oracle Restart configuration.

  Correct Answer: B

  About Startup Dependencies Oracle Restart ensures that Oracle components are started in the proper order, in accordance with component dependencies. For example, if database files are stored in Oracle ASM disk groups, then before starting the database instance, Oracle Restart ensures that the Oracle ASM instance is started and the required disk groups are mounted. Likewise, if a component must be shut down, Oracle Restart ensures that dependent components are cleanly shut down first. Oracle Restart also manages the weak dependency between database instances and the Oracle Net listener (the listener): When a database instance is started, Oracle Restart attempts to start the listener. If the listener startup fails, then the database is still started. If the listener later fails, Oracle Restart does not shut down and restart any database instances.

  References: http://docs.oracle.com/cd/E16655_01/server.121/e17636/restart.htm#ADMIN12710

• Question 109:

  Your multitenant container database (CDB) contains some pluggable databases (PDBs), you execute the following command in the root container:

  

  Which two statements are true? (Choose two.)

  A. Schema objects owned by the C# # A_ADMIN common user can be shared across all PDBs.

  B. The C##A_ADMIN user will be able to use the TEMP_TS temporary tablespace only in root.

  C. The command will create a common user whose description is contained in the root and each PDB.

  D. The schema for the common user C # # A_ADMIN can be different in each container.

  E. The command will create a user in the root container only because the CONTAINER clause is not

  used.

  Correct Answer: CD

• Question 110:

  You performed an incremental level 0 backup of a database:

  RMAN > BACKUP INCREMENTAL LEVEL 0 DATABASE;

  To enable block change tracking after the incremental level 0 backup, you issued this command:

  SQL > ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE '/mydir/ rman_change_track.f';

  To perform an incremental level 1 cumulative backup, you issued this command:

  RMAN> BACKUP INCREMENTAL LEVEL 1 CUMULATIVE DATABASE;

  Which three statements are true? (Choose three.)

  A. Backup change tracking will sometimes reduce I/O performed during cumulative incremental backups.

  B. The change tracking file must always be backed up when you perform a full database backup.

  C. Block change tracking will always reduce I/O performed during cumulative incremental backups.

  D. More than one database block may be read by an incremental backup for a change made to a single block.

  E. The incremental level 1 backup that immediately follows the enabling of block change tracking will not read the change tracking file to discover changed blocks.

  Correct Answer: ADE

  A: In a cumulative level 1 backup, RMAN backs up all the blocks used since the most recent level 0 incremental backup.

  E: Oracle Block Change Tracking Once enabled; this new 10g feature records the modified since last backup and stores the log of it in a block change tracking file using the CTW (Change Tracking Writer) process. During backups RMAN uses the log file to identify the specific blocks that must be backed up. This improves RMAN's performance as it does not have to scan whole datafiles to detect changed blocks. Logging of changed blocks is performed by the CTRW process which is also responsible for writing data to the block change tracking file.

  Note:

  * An incremental level 0 backup backs up all blocks that have ever been in use in this database.