Oracle Oracle Database 1Z0-060 Questions & Answers

• Question 171:

  Which three statements are true about Automatic Workload Repository (AWR)?

  A. All AWR tables belong to the SYSTEM schema.

  B. The AWR data is stored in memory and in the database.

  C. The snapshots collected by AWR are used by the self-tuning components in the database

  D. AWR computes time model statistics based on time usage for activities, which are displayed in the v$SYS time model and V$SESS_TIME_MODEL views.

  E. AWR contains system wide tracing and logging information.

  Correct Answer: BCD

  5.2 Overview of the Automatic Workload Repository The Automatic Workload Repository (AWR) collects, processes, and maintains performance statistics for problem detection and self-tuning purposes. This data is both in memory and stored in the database. The gathered data can be displayed in both reports and views.

  The statistics collected and processed by AWR include: Object statistics that determine both access and usage statistics of database segments Time model statistics based on time usage for activities, displayed in the V$SYS_TIME_MODEL and V$SESS_TIME_MODEL views

  References: http://docs.oracle.com/cd/B28359_01/server.111/b28274/autostat.htm#PFGRF02601

• Question 172:

  Which statement is true concerning dropping a pluggable database (PDB)?

  A. The PDB must be open in read-only mode.

  B. The PDB must be in mount state.

  C. The PDB must be unplugged.

  D. The PDB data files are always removed from disk.

  E. A dropped PDB can never be plugged back into a multitenant container database (CDB).

  Correct Answer: B

  http://docs.oracle.com/database/121/ADMIN/cdb_plug.htm#ADMIN13658

• Question 173:

  You notice a high number of waits for the db file scattered read and db file sequential read events in the recent Automatic Database Diagnostic Monitor (ADDM) report. After further investigation, you find that queries are performing too many full table scans and indexes are not being used even though the filter columns are indexed.

  Identify three possible reasons for this.

  A. Missing or stale histogram statistics

  B. Undersized shared pool

  C. High clustering factor for the indexes

  D. High value for the DB_FILE_MULTIBLOCK_READ_COUNT parameter

  E. Oversized buffer cache

  Correct Answer: ACD

  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.

• Question 174:

  Which three features work together, to allow a SQL statement to have different cursors for the same statement based on different selectivity ranges?

  A. Bind Variable Peeking

  B. SQL Plan Baselines

  C. Adaptive Cursor Sharing

  D. Bind variable used in a SQL statement

  E. Literals in a SQL statement

  Correct Answer: ACE

  * In bind variable peeking (also known as bind peeking), the optimizer looks at the value in a bind variable when the database performs a hard parse of a statement.

  When a query uses literals, the optimizer can use the literal values to find the best plan. However, when a query uses bind variables, the optimizer must select the best plan without the presence of literals in the SQL text. This task can be extremely difficult. By peeking at bind values the optimizer can determine the selectivity of a WHERE clause condition as if literals had been used, thereby improving the plan.

  C: Oracle 11g/12g uses Adaptive Cursor Sharing to solve this problem by allowing the server to compare the effectiveness of execution plans between executions with different bind variable values. If it notices suboptimal plans, it allows certain bind variable values, or ranges of values, to use alternate execution plans for the same statement. This functionality requires no additional configuration.

• Question 175:

  You upgrade your Oracle database in a multiprocessor environment. As a recommended best practice, you execute the following script:

  SQL > @utlrp.sql

  Which two actions does the script perform? (Choose two.)

  A. Parallel compilation of only the stored PL/SQL code

  B. Sequential recompilation of only the stored PL/SQL code

  C. Parallel recompilation of any stored PL/SQL code

  D. Sequential recompilation of any stored PL/SQL code

  E. Parallel recompilation of Java code

  F. Sequential recompilation of Java code

  Correct Answer: CE

  utlrp.sql and utlprp.sql

  The utlrp.sql and utlprp.sql scripts are provided by Oracle to recompile all invalid objects in the database.

  They are typically run after major database changes such as upgrades or patches. They are located in the

  $ORACLE_HOME/rdbms/ admin directory and provide a wrapper on the UTL_RECOMP package. The

  utlrp.sql script simply calls the utlprp.sql script with a command line parameter of "0". The utlprp.sql

  accepts a single integer parameter that indicates the level of parallelism as follows.

  0 - The level of parallelism is derived based on the CPU_COUNT parameter.

  1 - The recompilation is run serially, one object at a time.

  N - The recompilation is run in parallel with "N" number of threads.

  Both scripts must be run as the SYS user, or another user with SYSDBA, to work correctly.

• Question 176:

  What are two benefits of installing Grid Infrastructure software for a stand-alone server before installing and creating an Oracle database? (Choose two.)

  A. Effectively implements role separation

  B. Enables you to take advantage of Oracle Managed Files.

  C. Automatically registers the database with Oracle Restart.

  D. Helps you to easily upgrade the database from a prior release.

  E. Enables the Installation of Grid Infrastructure files on block or raw devices.

  Correct Answer: CE

  "Oracle Grid Infrastructure for a standalone server includes Oracle Restart and Oracle Automatic Storage Management. Oracle combined the two infrastructure products into a single set of binaries that is installed into an Oracle Restart home."

  References: http://docs.oracle.com/cd/E16655_01/install.121/e17735/oraclerestart.htm#NTDBI999

• Question 177:

  Identify two correct statements about multitenant architecture. (Choose two.)

  A. Multitenant architecture can be deployed only in a Real Application Clusters (RAC) configuration.

  B. Multiple pluggable databases (PDBs) share the SGA of a multitenant container database (CDB).

  C. Multiple CDBs share certain PDB resources.

  D. Multiple non-RAC CDB instances can mount the same PDB as long as they are on the same server.

  E. Patches are always applied at the CDB level.

  F. A PDB can have a private undo tablespace.

  Correct Answer: BE

  B: Using 12c Resource manager you will be able control CPU, Exadata I/O, sessions and parallel servers.

  A new 12c CDB Resource Manager Plan will use so-called "Shares" (resource allocations) to specify how

  CPU is distributed between PDBs. A CDB Resource Manager Plan also can use "utilization limits" to limit

  the CPU usage for a PDB. With a default directive, you do not need to modify the resource plan for each

  PDB plug and unplug.

  E: New paradigms for rapid patching and upgrades.

  The investment of time and effort to patch one multitenant container database results in patching all of its

  many pluggable databases. To patch a single pluggable database, you simply unplug/plug to a multitenant

  container database at a different Oracle Database software version.

  Incorrect Answers:

  A:

  *

  The Oracle RAC documentation describes special considerations for a CDB in an Oracle RAC environment.

  *

  Oracle Multitenant is a new option for Oracle Database 12c Enterprise Edition that helps customers reduce IT costs by simplifying consolidation, provisioning, upgrades, and more. It is supported by a new architecture that allows a container database to hold many pluggable databases. And it fully complements other options, including Oracle Real Application Clusters and Oracle Active Data Guard. An existing database can be simply adopted, with no change, as a pluggable database; and no changes are needed in the other tiers of the application.

  D: You can unplug a PDB from one CDB and plug it into a different CDB without altering your schemas or applications. A PDB can be plugged into only one CDB at a time.

  F:

  *

  UNDO tablespace can NOT be local and stays on the CDB level.

  *

  Redo and undo go hand in hand, and so the CDB as a whole has a single undo tablespace per RAC instance.

• Question 178:

  You must track all transactions that modify certain tables in the SALES schema for at least three years.

  Automatic undo management is enabled for the database with a retention of one day.

  Which two must you do to track the transactions? (Choose two.)

  A. Enable supplemental logging for the database.

  B. Specify undo retention guarantee for the database.

  C. Create a Flashback Data Archive in the tablespace where the tables are stored.

  D. Create a Flashback Data Archive in any suitable tablespace.

  E. Enable Flashback Data Archiving for the tables that require tracking.

  Correct Answer: DE

  E: By default, flashback archiving is disabled for any table. You can enable flashback archiving for a table if you have the FLASHBACK ARCHIVE object privilege on the Flashback Data Archive that you want to use for that table.

  D: Creating a Flashback Data Archive / Create a Flashback Data Archive with the CREATE FLASHBACK ARCHIVE statement, specifying the following: Name of the Flashback Data Archive Name of the first tablespace of the Flashback Data Archive

  (Optional) Maximum amount of space that the Flashback Data Archive can use in the first tablespace / Create a Flashback Data Archive named fla2 that uses tablespace tbs2, whose data will be retained for two years:

  CREATE FLASHBACK ARCHIVE fla2 TABLESPACE tbs2 RETENTION 2 YEAR;

• Question 179:

  You are the DBA supporting an Oracle 11g Release 2 database and wish to move a table containing several DATE, CHAR, VARCHAR2, and NUMBER data types, and the table's indexes, to another tablespace.

  The table does not have a primary key and is used by an OLTP application.

  Which technique will move the table and indexes while maintaining the highest level of availability to the application?

  A. Oracle Data Pump

  B. An ALTER TABLE MOVE to move the table and ALTER INDEX REBUILD to move the indexes.

  C. An ALTER TABLE MOVE to move the table and ALTER INDEX REBUILD ONLINE to move the indexes

  D. Online Table Redefinition

  E. Edition-Based Table Redefinition

  Correct Answer: D

  *

  Oracle Database provides a mechanism to make table structure modifications without significantly affecting the availability of the table. The mechanism is called online table redefinition. Redefining tables online provides a substantial increase in availability compared to traditional methods of redefining tables.

  *

  To redefine a table online:

  Choose the redefinition method: by key or by rowid

  *

  By key--Select a primary key or pseudo-primary key to use for the redefinition. Pseudo-primary keys are unique keys with all component columns having NOT NULL constraints. For this method, the versions of

  the tables before and after redefinition should have the same primary key columns. This is the preferred and default method of redefinition.

  *

  By rowid--Use this method if no key is available. In this method, a hidden column named M_ROW$$ is added to the post-redefined version of the table. It is recommended that this column be dropped or marked as unused after the redefinition is complete. If COMPATIBLE is set to 10.2.0 or higher, the final phase of redefinition automatically sets this column unused. You can then use the ALTER TABLE ... DROP UNUSED COLUMNS statement to drop it.

  You cannot use this method on index-organized tables.

  Note:

  * When you rebuild an index, you use an existing index as the data source. Creating an index in this manner enables you to change storage characteristics or move to a new tablespace. Rebuilding an index based on an existing data source removes intra-block fragmentation. Compared to dropping the index and using the CREATE INDEX statement, re-creating an existing index offers better performance.

  Incorrect Answers:

  E: Edition-based redefinition enables you to upgrade the database component of an application while it is in use, thereby minimizing or eliminating down time.

• Question 180:

  To implement Automatic Management (AMM), you set the following parameters:

  

  When you try to start the database instance with these parameter settings, you receive the following error message:

  

  Identify the reason the instance failed to start.

  A. The PGA_AGGREGATE_TARGET parameter is set to zero.

  B. The STATISTICS_LEVEL parameter is set to BASIC.

  C. Both the SGA_TARGET and MEMORY_TARGET parameters are set.

  D. The SGA_MAX_SIZE and SGA_TARGET parameter values are not equal.

  Correct Answer: B

  Example: SQL> startup force ORA-00824: cannot set SGA_TARGET or MEMORY_TARGET due to existing internal settings ORA-00848: STATISTICS_LEVEL cannot be set to BASIC with SGA_TARGET or MEMORY_TARGET