Oracle Oracle Certifications 1Z0-062 Questions & Answers

• Question 371:

  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:

  Not 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 372:

  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:

  

  SQL > startup ORA-00824: cannot set SGA_TARGET or MEMORY_TARGET due to existing internal settings, see alert log for more information.

  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

• Question 373:

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

  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: AC

  C: To use Oracle ASM or Oracle Restart, you must first install Oracle Grid Infrastructure for a standalone server before you install and create the database. Otherwise, you must manually register the database with Oracle Restart.

  Desupport of Block and Raw Devices With the release of Oracle Database 11g release 2 (11.2) and Oracle RAC 11g release 2 (11.2), using Database Configuration Assistant or the installer to store Oracle Clusterware or Oracle Database files directly on block or raw devices is not supported. If you intend to upgrade an existing Oracle RAC database, or an Oracle RAC database with Oracle ASM instances, then you can use an existing raw or block device partition, and perform a rolling upgrade of your existing installation.

  Performing a new installation using block or raw devices is not allowed.

• Question 374:

  On your Oracle 12c database, you invoked SQL *Loader to load data into the EMPLOYEES table in the HR schema by issuing the following command:

  $> sqlldr hr/hr@pdb table=employees

  Which two statements are true regarding the command? (Choose two.)

  A. It succeeds with default settings if the EMPLOYEES table belonging to HR is already defined in the database.

  B. It fails because no SQL *Loader data file location is specified.

  C. It fails if the HR user does not have the CREATE ANY DIRECTORY privilege.

  D. It fails because no SQL *Loader control file location is specified.

  Correct Answer: AC

  Note:

  * SQL*Loader is invoked when you specify the sqlldr command and, optionally, parameters that establish session characteristics.

• Question 375:

  After implementing full Oracle Data Redaction, you change the default value for the NUMBER data type as follows:

  

  After changing the value, you notice that FULL redaction continues to redact numeric data with zero.

  What must you do to activate the new default value for numeric full redaction?

  A. Re-enable redaction policies that use FULL data redaction.

  B. Re-create redaction policies that use FULL data redaction.

  C. Re-connect the sessions that access objects with redaction policies defined on them.

  D. Flush the shared pool.

  E. Restart the database instance.

  Correct Answer: E

  About Altering the Default Full Data Redaction Value You can alter the default displayed values for full Data Redaction polices. By default, 0 is the redacted value when Oracle Database performs full redaction (DBMS_REDACT.FULL) on a column of the NUMBER data type. If you want to change it to another value (for example, 7), then you can run the DBMS_REDACT.UPDATE_FULL_REDACTION_VALUES procedure to modify this value. The modification applies to all of the Data Redaction policies in the current database instance. After you modify a value, you must restart the database for it to take effect.

  Note:

  *

  The DBMS_REDACT package provides an interface to Oracle Data Redaction, which enables you to mask (redact) data that is returned from queries issued by low-privileged users or an application.

  *

  UPDATE_FULL_REDACTION_VALUES Procedure

  This procedure modifies the default displayed values for a Data Redaction policy for full redaction.

  *

  After you create the Data Redaction policy, it is automatically enabled and ready to redact data.

  *

  Oracle Data Redaction enables you to mask (redact) data that is returned from queries issued by low-privileged users or applications. You can redact column data by using one of the following methods:

  / Full redaction. / Partial redaction. / Regular expressions. / Random redaction. / No redaction.

• Question 376:

  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 377:

  Which three statements are true concerning unplugging a pluggable database (PDB)? (Choose three.)

  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.

  Correct Answer: BDE

  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.

• Question 378:

  Examine the following command:

  CREATE TABLE (prod_id number(4),

  Prod_name varchar2 (20),

  Category_id number(30),

  Quantity_on_hand number (3) INVISIBLE);

  Which three statements are true about using an invisible column in the PRODUCTS table? (Choose three.)

  A. The %ROWTYPE attribute declarations in PL/SQL to access a row will not display the invisible column in the output.

  B. The DESCRIBE commands in SQL *Plus will not display the invisible column in the output.

  C. Referential integrity constraint cannot be set on the invisible column.

  D. The invisible column cannot be made visible and can only be marked as unused.

  E. A primary key constraint can be added on the invisible column.

  Correct Answer: ABE

  AB: You can make individual table columns invisible. Any generic access of a table does not show the invisible columns in the table. For example, the following operations do not display invisible columns in the output:

  *

  SELECT * FROM statements in SQL

  *

  DESCRIBE commands in SQL*Plus

  *

  %ROWTYPE attribute declarations in PL/SQL

  *

  Describes in Oracle Call Interface (OCI)

  Incorrect:

  Not D: You can make invisible columns visible.

  You can make a column invisible during table creation or when you add a column to a table, and you can

  later alter the table to make the same column visible.

• Question 379:

  You wish to enable an audit policy for all database users, except SYS, SYSTEM, and SCOTT.

  You issue the following statements:

  SQL> AUDIT POLICY ORA_DATABASE_PARAMETER EXCEPT SYS; SQL> AUDIT POLICY ORA_DATABASE_PARAMETER EXCEPT SYSTEM; SQL> AUDIT POLICY ORA_DATABASE_PARAMETER EXCEPT SCOTT;

  For which database users is the audit policy now active?

  A. All users except SYS

  B. All users except SCOTT

  C. All users except sys and SCOTT

  D. All users except sys, system, and SCOTT

  Correct Answer: B

  If you run multiple AUDIT statements on the same unified audit policy but specify different EXCEPT users, then Oracle Database uses the last exception user list, not any of the users from the preceding lists. This means the effect of the earlier AUDIT POLICY ... EXCEPT statements are overridden by the latest AUDIT POLICY ... EXCEPT statement.

  Note:

  *

  The ORA_DATABASE_PARAMETER policy audits commonly used Oracle Database parameter settings. By default, this policy is not enabled.

  *

  You can use the keyword ALL to audit all actions. The following example shows how to audit all actions on the HR.EMPLOYEES table, except actions by user pmulligan.

  Example Auditing All Actions on a Table CREATE AUDIT POLICY all_actions_on_hr_emp_pol ACTIONS ALL ON HR.EMPLOYEES;

  AUDIT POLICY all_actions_on_hr_emp_pol EXCEPT pmulligan;

• Question 380:

  Examine this command:

  SQL > exec DBMS_STATS.SET_TABLE_PREFS (`SH', `CUSTOMERS', `PUBLISH', `false');

  Which three statements are true about the effect of this command? (Choose three.)

  A. Statistics collection is not done for the CUSTOMERS table when schema stats are gathered.

  B. Statistics collection is not done for the CUSTOMERS table when database stats are gathered.

  C. Any existing statistics for the CUSTOMERS table are still available to the optimizer at parse time.

  D. Statistics gathered on the CUSTOMERS table when schema stats are gathered are stored as pending statistics.

  E. Statistics gathered on the CUSTOMERS table when database stats are gathered are stored as pending statistics.

  Correct Answer: CDE

  *

  SET_TABLE_PREFS Procedure

  This procedure is used to set the statistics preferences of the specified table in the specified schema.

  *

  Example: Using Pending Statistics

  Assume many modifications have been made to the employees table since the last time statistics were gathered. To ensure that the cost-based optimizer is still picking the best plan, statistics should be gathered once again; however, the user is concerned that new statistics will cause the optimizer to choose bad plans when the current ones are acceptable. The user can do the following:

  EXEC DBMS_STATS.SET_TABLE_PREFS('hr', 'employees', 'PUBLISH', 'false');

  By setting the employees tables publish preference to FALSE, any statistics gather from now on will not be automatically published. The newly gathered statistics will be marked as pending.