Oracle Oracle Certifications 1Z0-062 Questions & Answers

• Question 361:

  An application accesses a small lookup table frequently. You notice that the required data blocks are getting aged out of the default buffer cache.

  How would you guarantee that the blocks for the table never age out?

  A. Configure the KEEP buffer pool and alter the table with the corresponding storage clause.

  B. Increase the database buffer cache size.

  C. Configure the RECYCLE buffer pool and alter the table with the corresponding storage clause.

  D. Configure Automata Shared Memory Management.

  E. Configure Automatic Memory Management.

  Correct Answer: A

  Schema objects are referenced with varying usage patterns; therefore, their cache behavior may be quite different. Multiple buffer pools enable you to address these differences. You can use a KEEP buffer pool to maintain objects in the buffer cache and a RECYCLE buffer pool to prevent objects from consuming unnecessary space in the cache. When an object is allocated to a cache, all blocks from that object are placed in that cache. Oracle maintains a DEFAULT buffer pool for objects that have not been assigned to one of the buffer pools.

• Question 362:

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

  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: ACD

• Question 363:

  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

  Correct Answer: A

• Question 364:

  You want to capture column group usage and gather extended statistics for better cardinality estimates for the CUSTOMERS table in the SH schema.

  Examine the following steps:

  1.

  Issue the SELECT DBMS_STATS.CREATE_EXTENDED_STATS (`SH', `CUSTOMERS') FROM dual statement.

  2.

  Execute the DBMS_STATS.SEED_COL_USAGE (null, `SH', 500) procedure.

  3.

  Execute the required queries on the CUSTOMERS table.

  4.

  Issue the SELECT DBMS_STATS.REPORT_COL_USAGE (`SH', `CUSTOMERS') FROM dual statement.

  Identify the correct sequence of steps.

  A. 3, 2, 1, 4

  B. 2, 3, 4, 1

  C. 4, 1, 3, 2

  D. 3, 2, 4, 1

  Correct Answer: B

  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 statisticsHere 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.

• Question 365:

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

  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

• Question 366:

  You upgraded your database from pre-12c to a multitenant container database (CDB) containing pluggable databases (PDBs).

  Examine the query and its output:

  

  Which two tasks must you perform to add users with SYSBACKUP, SYSDG, and SYSKM privilege to the password file? (Choose two.)

  A. Assign the appropriate operating system groups to SYSBACKUP, SYSDG, SYSKM.

  B. Grant SYSBACKUP, SYSDG, and SYSKM privileges to the intended users.

  C. Re-create the password file with SYSBACKUP, SYSDG, and SYSKM privilege and the FORCE argument set to No.

  D. Re-create the password file with SYSBACKUP, SYSDG, and SYSKM privilege, and FORCE arguments set to Yes.

  E. Re-create the password file in the Oracle Database 12c format.

  Correct Answer: BD

  * orapwd

  / You can create a database password file using the password file creation utility, ORAPWD.

  The syntax of the ORAPWD command is as follows:

  orapwd FILE=filename [ENTRIES=numusers] [FORCE={y|n}] [ASM={y|n}]

  [DBUNIQUENAME=dbname] [FORMAT={12|legacy}] [SYSBACKUP={y|n}] [SYSDG={y|n}]

  [SYSKM={y|n}] [DELETE={y|n}] [INPUT_FILE=input-fname]

  force - whether to overwrite existing file (optional),

  * v$PWFILE_users / 12c: V$PWFILE_USERS lists all users in the password file, and indicates whether the user has been granted the SYSDBA, SYSOPER, SYSASM, SYSBACKUP, SYSDG, and SYSKM privileges.

  / 10c: sts users who have been granted SYSDBA and SYSOPER privileges as derived from the password

  file.

  ColumnDatatypeDescription

  USERNAMEVARCHAR2(30)The name of the user that is contained in the password file

  SYSDBAVARCHAR2(5)If TRUE, the user can connect with SYSDBA privileges

  SYSOPERVARCHAR2(5)If TRUE, the user can connect with SYSOPER privileges

  Incorrect:

  not E: The format of the v$PWFILE_users file is already in 12c format.

• Question 367:

  Identify two correct statements about multitenant architectures.

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

  B. Multiple pluggable databases (PDBs) share certain multitenant container database (CDB) resources.

  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: Not 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. Not 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.

  not 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 368:

  You upgrade your Oracle database in a multiprocessor environment. As a recommended 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 369:

  Which two statements are true concerning dropping a pluggable database (PDB)? (Choose two.)

  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: BC

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

• Question 370:

  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.