ANSWERS

Oracle 10g Fundamental Exam Answers

NOTE: The answers go with their sequences. If a question was not answer, that means that it a repeating question and the answer was given by the previous questions or it is not in the scope of this subject.

Answers:

Regular Expression

Q:   What is Regular Expression  (REGEXP) in the Oracle 10g Database?

A:   It is a method for simple and complex patterns for searching and manipulating a text. You can search, extract, format, and manipulate a text in the database. At the beginning, it appears that the syntax is not very intuitive but by second look, it may look easy. The technique more reflects as UNIX style regular expressions.

Q:   What are functions of REGEXP?

A:   Interfaces: Oracle Regular Expressions are implemented by the following functions available in SQL and PL/SQL.

• REGEXP_LIKE ,

• REGEXP_REPLACE ,

• REGEXP_INSTR , and

• REGEXP_SUBSTR

Q:   What are the Metacharacters in REGEXP?

Metacharacters: The following is a list of supported Oracle metacharacters use in Oracle Regular Expressions.

Q:   What are the Character Classes?

A:   Character Classes:  They are sensitive to the underlying character set such as the [:lower:] character class.

The following is a list of Oracle supports character classes , based on character class definitions in NLS classification data:

Q:   Consider a simple query to convert the ‘McLean’ city name to a more readable format (Mc Lean). You should look for any instance for a lower case letter immediately followed by an upper case letter. Your query should record these two letters in backreferences by using subexpressions, then replaces the first one, followed by a space, then followed by the second letter.

A:  

SQL> SELECT

                        REGEXP_REPLACE (‘McLean’,

                        ‘([[:lower:]])([[:upper:]])’, ‘\1 \2’) as “City”

            FROM dual;

Q:   How to use REGULAR EXPRESSIONS in Oracle

A:    Keep this in your mind that these functions support CHAR, VARCHAR2, CLOB, NCHAR, NVARCHAR, and NCLOB datatypes.

Q:   What does the REGEXP_LIKE  function?

A:   It returns a Boolean indicating whether the pattern matched or not.

Q:   Consider to write an expression that could search for common inflections of the verb ‘try’.

A:   The following regular expression will match try, trying, tried, and tries.

SQL> SELECT

                       REGEXP_LIKE  (‘We are trying to make the subject easier.’,

                                                ‘tr(y(ing)? | (ied) | (ies))’) as REGEXT_SAMPLE

            FROM dual;

Q:   What does the REGEXP_SUBSTR  function?

A:   It returns the actual data that matches the specified pattern.

Q:   Consider to write an expression that could return the ‘trying’ specified pattern.

A:

SQL> SELECT

                       REGEXP_SUBSTR  (‘We are trying to make the subject easier.’,

                                                ‘tr(y(ing)? | (ied) | (ies))’) as REGEXT_SAMPLE

            FROM dual;

Q:   What does the REGEXP_INSTR  function?

A:   It returns the character position of either the beginning or end of the match.

Q:   Consider to write an expression that could return the position of ‘trying’ specified pattern.

A:  

SQL> SELECT

                       REGEXP_INSTR  (‘We are trying to make the subject easier.’,

                                                ‘tr(y(ing)? | (ied) | (ies))’) as REGEXT_SAMPLE

            FROM dual;

Q:   What does the REGEXP_REPLACE  function?

A:   It looks for an occurrence of a regular expression and replaces it with the contents of a supplied text literal.

Q:   Query a list of all employees’ name that hired between 1996 and 1999.

A:

SQL> SELECT ename FROM emp

            WHERE REGEXP_REPLACE

                        (TO_CHAR(hire_date, ‘YYYY’), ‘^199[6-9]$’);

You used ‘^’ to indicate that the beginning of the line has to be 199, and [-] with $ to specify range of valid characters.

Q:   What is occurrence in the REGEXP functions?

A:   All functions take an occurrence that specifies you require the nth matching expression in REGEXP_SUBSTR  and REGEXP_INSTR , the default for which is 1.

Q:   Consider extracting the third field being the Oracle system identification in a column.

A:

SQL> SELECT

            REGEXP_SUBSTR (‘system/password@myhost:1521:mysid’,

            ‘[^:]+’, 1, 3) as “SID name”

            FROM dual;

UNDO Advisor

Q:   What is the UNDO advisor?

A:   You can size your UNDO tablespace  with the UNDO Advisor . The Snapshot Too Old  error will be noted in the database alert history. Assuming that the UNDO tablespace is UNDOTBS1, to check the time and problem on the UNDO tablespace do the following.

SQL> SELECT time_suggested, reason

            FROM dba_alert_history

            WHERE object_name = ‘UNDOTBS1’

            /

You can use the Database Control home page to utilize the UNDO Advisor  to get recommendations to correct the problem. From the Database Control home page, click on the Administration tab and then UNDO Management. On that page change the Analysis Time Period field to Last One Hour and click the Update Analysis button. Now, you should see a recommendation from UNDO Advisor. You should be able also to change the size and apply the changes.

Q:   How do you check the time and problem on the UNDO tablespace ?

A:

SQL> SELECT time_suggested, reason

            FROM dba_alert_history

            WHERE object_name = ‘UNDOTBS1’

            /

To correct the problem: You can use the Database Control home page to utilize the UNDO Advisor  to get recommendations to correct the problem. From the Database Control home page, click on the Administration tab and then UNDO Management. On that page change the Analysis Time Period field to Last One Hour and click the Update Analysis button. Now, you should see a recommendation from UNDO Advisor. You should be able also to change the size and apply the changes.

The Oracle Data Pump  Export and Import utilities

Q:   Why do you use Data Pump  Export and Import?

A:   The expdp  and impdp  tools support all the original exp and imp functionalities plus many new features. With previous release, you could only move the transportable tablespace across Oracle databases that were running on the same architecture and operating system. With Data Pump , you are able to transport data files from one plateform to another. Only you have to make sure that both source and target databases set their COMPATIBLE initialization parameter to 10.0.0 or greater

Q:   Export the DEPT and EMP records that deptno is 10 or 30 from the ISELF schema.

A:

# expdp  

FILE=/u02/oradata/ora10g/EXPDAT02.DMP

FILESIZE=2048M

LOG= /u02/oradata/ora10g/EXPDAT.LOG

TABLES=ISELF.CUSTOMER,ISELF.DEPT,ISELF.EMP

GRANTS=y

INDEXES=y

ROWS=y

CONSTRAINTS=y

CONSISTENT=n

RECORD=n

QUERY='WHERE deptno IN (10, 30)'

Q:   Export the iself, outln and system schemas.

A:

# expdp  

FILE=/u02/oradata/ora10g/EXPDAT05.DMP

FILESIZE=2048M

LOG= /u02/oradata/ora10g/EXPDAT.LOG

OWNER=ISELF,OUTLN,SYSTEM

GRANTS=y

INDEXES=y

ROWS=y

CONSTRAINTS=y

CONSISTENT=n

RECORD=n

Q:   How do you import the DEPT and EMP tables with recalculating statistics and committing after each array insert?

A:

# impdp  

FILE=/u02/oradata/ora10g/EXPDAT.DMP

LOG= /u02/oradata/ora10g/IMPORT.LOG

FROMUSER=iself

TABLES=emp,dept

GRANTS=y

INDEXES=y

ROWS=y

CONSTRAINTS=y

IGNORE=y

COMMIT=y

RECALCULATE_STATISTICS=y

DATAFILES=n

Q:  Perform a Parallel Full Export on the DIR1, DIR2 directory objects and make sure that each file be 2 GB in size.

A:

$ expdp

FULL=y

PARALLEL=2

DUMPFILE=DIR1:exp1%U.dmp, DIR2:exp2%U.dmp

FILESIZE=2G

The %u implies that multiple files may be generated and start at 01 with a two-digital number.

Q:   Export only all functions, tables, procedures (proc1 and proc2 only), and all views that starts with the ‘EMP’ characters from the iself and SCOTT schemas.

A:

$ expdp

SCHEMAS=iself,scott

DIRECTORY=private_exp_space

DUMPFILE=expdat01.dmp

INCLUDE=function

INCLUDE=table

INCLUDE=procedure:”in (‘proc1’,’proc2’)”

INCLUDE=view:”like ‘EMP%’”

Either you should use INCLUDE or EXCLUDE.

Q:   Generate a SQL script from an existing export dump file.

A:

$ impdp

DIRECTORY=private_exp_space

DUMPFILE=expdat01.dmp

SQLFILE=MyScript.sql

Q:   Move objects from one tablespace to another by using the REMAP_TABLESPACE option.

A:

$ impdp

SCHEMAS=iself

REMAP_TABLESPACE=iself_tablespace:urself_tablespace

Q:   How can you read from your exported file directly without importing them into your database?

A:

SQL> CREATE TABLE external_emp

            (ename, sal, comm)

            ORGANIZATION EXTERNAL

            (

            TYPE ORACLE_DATAPUMP

            DEFAULT DIRECTORY  private_exp_space

            LOCATION ( ‘expdat01.dmp’)

            )

            PARALLEL AS

            SELECT  ename, sal, comm.

            FROM emp WHERE deptno IN (10, 30);

Q:   What is an endian format?

A:   The endian format or Byte ordering is a format that will affect the results when data is written and read. For example, the 2-bytes integer value 1 is written as 0x0001 on a big-endian system and as 0x0100 on a little-endian system. To determine the endian format of a platform do the following query:

SQL> SELECT p.endian_format

            FROM v$transportable_platform p, v$database  d

            WHERE p.platform_name = d.platform_name

            /

The v$transportable_platform view contains all supported platforms. In order to convert form one platform to another platform uses the rman utility. The following is an example of how to convert from one platform to another.

$ rman TARGET=/

 RMAN> CONVERT DATAFILE ‘/local/oradata/school/*’

            FROM PLATFORM = ‘Solari [tm] OE (32-bit)’

            DB_FILE_NAME_CONVERT  =

            ‘/local/oradata/school/data’ , ‘/remote/oradata/data’;

Backup and Recovery Enhancements

Q:   What is the Flash Recovery Area ?

A:   It is a unified storage location for all recovery-related files and activities in an Oracle Database. It includes Control File, Archived Log Files, Flashback  Logs , Control File Autobackups, Data Files, and RMAN files.

Q:   How do you define a Flash Recovery Area ?

A:   To define a Flash Recovery Area  set the following Oracle Initialization Parameters.

SQL> ALTER SYSTEM SET db_recovery_file_dest_size = 100G;

SQL> ALTER SYSTEM SET db_recovery_file_dest = ‘/u10/oradata/school’;

Q:   How do you use the V$RECOVERY_FILE_DEST  view to display information regarding the flash recovery area?

A:

SQL> SELECT name, space_limit, space_used,

            space_reclaimable, number_of_files

            FROM v$recovery_file_dest;

Q:   How can you display warning messages?

A:

SQL> SELECT object_type, message_type,

            message_level, reason, suggested_action

            FROM dba_outstanding_alerts ;

Q:   How do you backup the Flash Recovery Area ?

A:

RMAN> BACKUP RECOVERY  FILES;

The files on disk that have not previously been backed up will be backed up. They are full and incremental backup sets, control file auto-backups, archive logs, and datafile copies.

Q:   How to use the best practice to use Oracle Managed File (OMF) to let Oracle database to create and manage the underlying operating system files of a database?

A:

SQL> ALTER SYSTEM SET

                        db_create_file_dest = ‘/u03/oradata/school’;

SQL> ALTER SYSTEM SET

                        db_create_online_dest_1 = ‘/u04/oradata/school’;

Q:   How to enable Fast Incremental Backup to backup only those data blocks that have changed?

A:

SQL> ALTER DATABASE enable BLOCK CHANGE TRACKING;

Q:   How do you monitor block change tracking?

A:

SQL> SELECT filename, status, bytes

            FROM v$block_change_tracking ;

It shows where the block change-tracking file is located, the status of it and the size.

Q:   How do you use the V$BACKUP_DATAFILE  view to display how effective the block change tracking is in minimizing the incremental backup I/O?

A:

SQL> SELECT file#, AVG(datafile_blocks), AVG(blocks_read),

            AVG (blocks_read/datafile_blocks), AVG(blocks)

            FROM v$backup_datafile

            WHERE used_change_tracking = ‘YES’ AND incremental_level > 0

            GROUP BY file#;

If the AVG (blocks_read/datafile_blocks) column is high then you may have to decrease the time between the incremental backups.

Q:   How do you backup the entire database?

A:

RMAN> BACKUP DATABASE ;

Q:   How do you backup an individual tablespaces?

A:

RMAN> CONFIGURE DEFAULT DEVICE  TYPE TO DISK;

RMAN> BACKUP TABLESPACE system;

Q:   How do you backup datafiles and control files?

A:

RMAN> BACKUP DATAFILE  3;

RMAN> BACKUP CURRENT CONTROLFILE;

Q:   Use a fast recovery without restoring all backups from their backup location to the location specified in the controlfile.

A:

RMAN> SWITCH DATABASE TO COPY;

RMAN will adjust the control file so that the data files point to the backup file location and then starts recovery.

Q:   How can you begin and end backup on the database level?

A:

SQL> ALTER DATABASE BEGIN BACKUP ;

Copy all the datafiles…

SQL> ALTER DATABASE END BACKUP;

Q:   How do you set the flash recovery area?

A:

SQL> ALTER SYSTEM SET db_recovery_file_dest_size = 100G;

SQL> ALTER SYSTEM SET db_recovery_file_dest = ‘/u10/oradata/school’;

Q:   How do you gather information regarding the flash recovery area?

A:

SQL> SELECT name, space_limit, space_used,

            space_reclaimable, number_of_files

            FROM v$recovery_file_dest;

The Flashback  feature

Q:   What is the flashback?

A:   The flashback gives users the capability to query past version of schema objects, query historical data, and perform change analysis.

Q:   How it works?

A:   Every transaction logically generates a new version of the database. You can navigate through these versions to find an error and its cause.

Q:   Why do need to use the flashback?

A:   It eliminates restore process and it is faster than traditional point-in-time recovery.

Q:   What is its architecture?

A:   Now, one more log was added as Flashback  Database log. The Oracle database server regularly logs before images of data blocks in the Flashback Database logs from Flashback buffer in the SGA Oracle memory. The Flashback Database must be enabled. When it is enabled, the new RVWR (Recovery Version Writer) background process will be started. The RVWR background process sequentially writes Flashback Database data from the flashback buffer to the Flashback Database logs which are circularly reused.

Q:   How do you configure Flashback  Database?

A:

Assuming:

The database is in archive mode.

The database flash recovery area was configured.

Set the database flashback retention time target.

SQL> ALTER SYSTEM SET db_flashback_retention_target  = 2880;   -- Ex: for two days.

Enable Flashback  Database. Before altering your database, the database must be in MOUNT EXCLUSIVE mode, ARCHIVELOG mode, and the Flashback be enabled. To check whether it is enable do the following SQL statement.

SQL> SELECT flashback_on FROM v$database ;

SQL> ALTER DATABASE FLASHBACK ON;

If you disable the flashback (OFF), all existing Flashback  Database logs are deleted automatically.

Q:   How do you Flashback  a database?

A:   The FLASHBACK DATABASE  command force the database back to a past time or SCN. See the following examples:

SQL> FLASHBACK DATABASE  TO TIMESTAMP (sysdate-5/24);  -- Go back 5 hours from now.

SQL> FLASHBACK DATABASE  TO SCN 65473;

Q:   How do you monitor Flashback  Database?

A:   Use the V$FLASHBACK_DATABASE_LOG  view to display the approximate lowest SCN and time to which you can flash back your database.

SQL> SELECT oldest_flashback_scn, oldest_flashback_time

            FROM v$flashback_database_log;

Q:   How do you use the V$FLASHBACK_DATABASE_LOG  view to determine how much disk space is needed to meet the current flashback retention target?

A:

SQL> SELECT estimated_flashback_size, flashback_size

            FROM v$flashback_database_log;

Q:   How do you use the V$FLASHBACK_DATABASE_STAT  view to monitor the overhead of logging flashback data?

A:   You can use this to adjust the retention time or the flash recovery area size.

SQL> SELECT * FROM v$flashback_database_stat;

Q:   How do you exclude a tablespace from flashback database?

A:   If you do not want the USER tablespace to be included to log Flashback  Database data, do the following SQL statement.

SQL> ALTER TABLESPACE users FLASHBACK OFF;

Q:   When are you not able to Flashback  Database?

A:

• The control file has been restored or recreated,

• A tablespace has been dropped,

• A data file has been shrunk, and

• A RESETLOSG operation is required.

Q:   How can you query the content of the recycle bin by using the DBA_RECYCLEBIN  view?

A:

SQL> SELECT * FROM dba_recyclebin WHERE can_undrop = ‘YES’;

SQL> SHOW RECYCLEBIN

Q:   How do you restore from recycle bin?

A:   Use the FLASHBACK TABLE  command to recover a table and all its possible dependent objects form the recycle bin.

SQL> DROP TABLE iself.emp;

SQL> SELECT original_name, object_name, type, ts_name,

            dropttime, related, space

            FROM dba_recyclebin

            WHERE original_name = ‘EMP’;

SQL> FLASHBACK TABLE  emp TO BEFORE DROP;

SQL> FLASHBACK TABLE  emp

            TO BEFORE DROP RENAME TO employee;

SQL> FLASHBACK TABLE  emp

            TO TIMESTAMP to_timestamp (’14:45’,’HH24:MI’);

Q:   How do you reclaim the recycle bin?

A:   By using PURG option.

SQL> PURGE TABLE emp;  -- Purges the specified table.

SQL> PURGE TABLESPACE scott_ts USER scott;  -- All the Scott’s objects.

SQL> PURGE RECYCLEBIN ;     -- Purges all user objects.

SQL> PURGE DBA_RECYCLEBIN ;   -- Purges all the objects.

Q:   How can you perform queries on the database as of a certain clock time or SCN?

A:

SQL> SELECT versions_xid, sal, versions_operation

            FROM emp

            VERSIONS BETWEEN TIMESTAMP sysdate-10/24 AND sysdate

            WHERE empno = 100;

Q:   How can you use the CURRENT_SCN column in the V$DATABASE view to obtain the current SCN?

A:

SQL> SELECT current_scn FROM v$database ;

Q:   How can you enforce to guaranteed UNDO retention?

A:   You can do one of the following SQL statements.

SQL> CREATE UNDO TABLESPACE my_undotbs1

            DATAFILE ‘my_undotbs01.dbf’ SIZE 10G AUTOEXTEND ON

            RETENTION GUARANTEE;

SQL> ALTER TABLESPACE my_undotbs1

            RETENTION GUARANTEE;

Q:   How can you check the UNDO retention?

A:

SQL> SELECT tablespace_name, retention FROM dba_tablespaces;

Q:   How can you recover deleted file?

A:

Connect as sysdba and flashback the table.

SQL> CONNECT / AS SYSDBA

Use the FLASHBACK TABLE  command to recover a table and all its possible dependent objects form the recycle bin.

Check what do you have in your recycle bin.

SQL> SELECT original_name, object_name, type, ts_name,

            dropttime, related, space

            FROM dba_recyclebin

            WHERE original_name = ‘FLASHBACK_TABLE’

            /

SQL> FLASHBACK TABLE  iself.emp TO BEFORE DROP;

Q:   How do you test that your recovery was successful?

A:

SQL> SELECT count(*) FROM flashback_table;

Automatic Database Diagnostic Monitor

Q:   What does the Automatic Database Diagnostic Monitor ?

A:   The Automatic Database Diagnostic Monitor  (ADDM ) maintains a self-diagnostic to a database. It will either perform a treatment or refer it to specialists such as the SQL tuning advisor.

Q:   How does ADDM  work?

A:   The Oracle database automatically gathers statistics from the SGA every 60 minutes and stores them in the Automatic Workload Repository  (AWR ) in the form of snapshots. These snapshots are similar to STATSPACK  snapshots. The MMON process, it is a process that schedules the ADDM  to run automatically to detect problems proactively for every two last snapshots. It is possible also to invoke an ADDM analysis manually.

Q:   Where can I access the latest ADDM  run?

A:   Go to the Database Control home page, on the Diagnostic Summary section you will see the number of ADDM  finding from the previous automatic run. Click on the Performance Findings link. The Automatic Database Diagnostic Monitor  (ADDM) page will be display with the details of the latest ADDM run.

Q:   How can I turn the ADDM  process off?

A:   By default the ADDM  process is enabled since the STATISTICS_LEVEL initialization parameter is TYPICAL. By setting these parameters to BASIC, it will stop to run automatically.

Q:   How can you check your ADDM  default setting?

A:   Execute the following SQL statement.

SQL> SELECT parameter_value, is_default

            FROM dba_advisor_def_parameters

            WHERE advisor_name = ‘ADDM ’

            /

Q:   How can I retrieve ADDM  Reports using SQL?

A:   You should type the following SQL statement to display the most recent ADDM  report using a SQL command.

SQL> SELECT dbms_advisor .GET_TASK_REPORT(task_name)

            FROM dba_advisor_tasks

            WHERE task_id = (SELECT max(t.task_id)

                        FROM dba_advisor_tasks  t, dba_advisor_log l

                        WHERE t.task_id = l.task_id AND t.advisor_name = ‘ADDM ’

                                    AND l.status = ‘COMPLETED’

            /

or

SQL> @$ORACLE_HOME/rdbms/addmrpt

Q:   What is the Automatic Shared Memory Management  (MMAN )?

A:   It maintains the management of the most important shared memory structures. For example, if your system runs OLTP  during the day and large parallel batch jobs at night, you may not need to decrease buffer cache and increase large pool in order to satisfy the needs of your nightly jobs. The MMAN  background process should do that.

Q:   How do you enable or disable Automatic Shared Memory Management ?

A:   Go to your Database Control page. Click on the Administration tab, select Memory Parameters under the Instance heading, and click the SGA tab. Now, you are able to enable or disable. When you enable it, you can enter the total SGA size or the SGA_TARGET  value.  If you set SGA_TARGET to 0, Automatic Shared Memory Management  will be disabled.

Q:   How do you determine the actual size of the auto-tuned components in the SGA?

A:   When the SGA_TARGET  value is set to no-zero, you can determine the actual size of the auto-tuned components in the SGA by the following SQL statement.

SQL> SELECT component, current_size/1024/1024

            FROM v$sga_dynamic_components

            /

Notice that if the SGA_TARGET  value is no-zero and no value for an auto-tuned SGA parameter, then the values of the auto-tuned SGA parameters in the v$parameter  view is 0. You will see the values if you assigned a value for any of the auto-tuned parameters.

SQL> SELECT name, value, isdefault

            FROM v$parameter

            WHERE name LIKE ‘%size’

            /

Q:   How do you change the SGA_TARGET  value?

A:   You can change it by using the ALTER SYSTEM command dynamically. The value can be increased up to the value of SGA_MAX_SIZE .

Q:   What is Automatic Checkpoint Tuning?

A:   It will make the best effort to write out dirty buffers without adverse impact on the database automatically. To enable it you should set the FAST_START_MTTR_TARGET  value to a nonzero value and all the checkpoint parameters will be ignored.

Oracle Manageability Infrastructure

Q:   What are the components of Oracle manageability Infrastructure?

A:               Automated tasks

            Server-Generated alerts

            Advisory Framework

            Automatic Workload Repository

Q:   Describe Automatic Routine Administration tasks:

A:   You can use the Scheduler , to submit a task that needs to be performed for keeping the database in tune. To add a task, go to the Database Control home page, click on the Administration tab, click the Jobs link in the Scheduler section, and then create the task. You may add a task using PL/SQL. See the following example: Assuming that you have already created the ONLINE_BKUP procedure to perform online backup. You now want to add that task to the WEEKEND_WINDOW.

SQL> BEGIN

            DBMS_SCHEDULER .CREATE_JOB  (

                        Job_name        =>            ‘online_bkup’,

                        Job_type          =>            ‘STORED_PROCEDURE’,

                        Job_action         =>            ‘myonline_backup’,

                        Job_class         =>             ‘AUTO_TASKS_JOB_CLASS ’,

                        Scheduler _name=>            ‘WEEKEND_WINDOW’);

         END;

            /

Q:   Describe Server-Generated alerts :

A:   If a problem was detected, the Oracle server will send an (email) alert message with possible corrective actions. The difference between Enterprise Manager Alerts and Server-Generated alerts  is mainly that the metrics threshold validations are performed by MMON, which unlike Enterprise Manager should access SGA. These alerts appear in DBA_OUTSTANDING_ALERTS and, when cleared, they go to DBA_ALERT_HISTORY. To set alert thresholds, go to database home page, click Manage Metrics in the Related links section. Then click the Edit Thresholds button. You can also use the DBMS_SERVER_ALERT .SET_THRESHOLD procedure. For example:

SQL> BEGIN

            DBMS_SERVER_ALERT .SET_THRESHOLD (

                        DBMS_SERVER_ALERT .CPU_TIME_PER_CALL,

                        DBMS_SERVER_ALERT .OPERATOR_GE, ‘8000’,

                        DBMS_SERVER_ALERT .OPERATOR_GE, ‘10000’, 1, 2, ‘school’,

                        DBMS_SERVER_ALERT .OBJECT_TYPE_SERVICE, ‘payroll’);

         END;

            /

Q:   Describe Advisory Framework :

A:   They are server components that provide a DBA with useful feedback about a database resource utilization and performance. The following are the list of advisors: ADDM , SQL Tuning Advisor, SQL Access Advisor , PGA Advisor, SGA Advisor, Segment Advisor , and UNDO Advisor . To open the Advisors Central page, go to the Database Control home and click on the Advisor Central link in the list of Related Links. The DBMS_ADVISOR package contains all constants and procedure declarations you need for all advisors. There are Advisor views such as DBA_ADVISOR_{TASKS | LOG | OBJECTS | RECOMMENDATIONS | ACTIONS}.

Q:   What is Automatic Workload Repository  (AWR )?

A:   It provides services to Oracle components to collect, maintain, process, and access performance statistics for problem detection and self-tuning purposes. The MMON (Manageability Monitor) background process will transfer the memory version of the statistics every 60 minutes to disk on a regular basis and MMNL (Manageability Monitor Light) whenever the buffer is full. The workload repository resides in the SYSAUX tablespace . A baseline can be identified by executing the DBMS_WORKLOAD_REPOSITORY.CREATE_BASELINE procedure. To run Automatic Workload Repository  Reports run the following SQL script. 

SQL> @$ORACLE_HOME/rdbms/admin/awrrpt

Q:   Manually invoke the ADDM  advisor to analyze the database between snapshots 60 and 66. Then, use the task name to get the results from the analysis

A:   Define a binding variable to hold the task name and another variable to hold task id.

SQL> VARIABLE tname VARCHAR2 (60)

SQL> VARIABLE taskid NUMBER

Create an advisor task of the particular ADDM  type.

SQL> EXEC dbms_advisor .create_task(‘ADDM ’, :taskid, :tname);

Set the required parameters to run this specific type of task.

SQL> EXEC dbms_advisor .set_task_parameter(:tname, ‘START_SNAPSHOT’, 60);

SQL> EXEC dbms_advisor .set_task_parameter(:tname, ‘END_SNAPSHOT’, 66);

Execute the task.

SQL> EXEC dbms_advisor .execute_task(:tname);

Use the task name to get the results from the analysis.

SQL> SELECT dbms_advisor .get_task_report(:tname)

            FROM dba_advisor_tasks  t

            WHERE t.task_name = :tname AND

                        t.owner = SYS_CONTEXT (‘userenv’, ‘session_user’)

            /

Q:   As sysdba, create a special procedure to de-queue alert information from the ALERT_QUE. Then give an object privilege to SYSTEM to use it.

A:   Logging into SQL*PLUS as sysdba

SQL> CONNECT / as sysdba

Add a new subscriber ALERT_MYUSERS to the internal ALERT_QUE queue.

SQL> EXEC dbms_aqadm .add_subscriber (

            ‘SYS.ALERT_QUE’, AQ$_AGENT(‘ALERT_MYUSERS’,’’,0));

Grant user SYSTEM the right to dequeue from the ALERT_QUE.

SQL> BEGIN

            dbms_aqadm .enable_db_access(

                        agent_name=>’ALERT_MYUSERS’,db_username=>’SYSTEM’);

          END;

SQL> BEGIN

            dbms_aqadm .grant_queue_privilege (

                        Privilege=>’DEQUEUE’,

                        queue_name=>’ALERT_QUE’,

                        Grantee=>’SYSTEM’);

          END;

Now, write a Stored PL/SQL procedure that is used by user SYSTEM to dequeue alert information from the ALERT_QUE.

SQL> CREATE OR REPLACE PROCEDURE my_dequeue IS

            dequeue_options            dbms_aq.dequeue_options_t;

            message_properies            dbms_aq.message_properties_t;

            message                      ALERT_TYPE;

            message_handle            RAW(16);

         BEGIN

            dequeue_options.consumer_name := ‘ALERT_MYUSERS’;

            dequeue_options.wait := dbms_aq.no_wait;

            dequeue_options.naviagtion := dbms_aq.first_message;

            dequeue_options.dequeue_mode := dbms_aq.remove;

            dbms_aq.dequeue (

                        queue_name                =>            ‘SYS.ALERT_QUE’,

                        dequeue_options            =>            dequeue_options,

                        message_properties            =>            message_properties,

                        payload                         =>            message,

                        msgid                           =>            message_handle);

            Dbms_output.put_line(‘This is my alert message dequeue…’);

         END;

            /

Grant ‘EXECUTE’ object privilege on MY_DEQUEUE to SYSTEM.

SQL> GRANT EXECUTE ON MY_DEQUEUE TO SYSTEM;

Q:   Set the USER Commits Per Sec metric with a warning threshold set 3, and a critical threshold set to 7. Your observation period should be for one minute, and the number of consecutive occurrences should be set to two.

A:  

SQL> BEGIN

            DBMS_SERVER_ALERT .set_threshold (

                        DBMS_SERVER_ALERT .user_commits_sec,

                        DBMS_SERVER_ALERT .operator_ge, 3,

                        DBMS_SERVER_ALERT .operator_ge, 7,

                        1,2, ‘school’,

                        DBMS_SERVER_ALERT .object_type_system, null);

         END:

Check that the metrics thresholds have been set.

SQL> COL object_name FORMAT a30

SQL> COL metrics_name FORMAT a30

SQL> COL warning_value FORMAT a10

SQL> COL critical_value FORMAT a10

SQL> SELECT object_name, metrics_name, warning_value, critical_value

            FROM dba_thresholds;

Q:   How do you examine your outstanding alerts and alert history?

A:  

SQL> SELECT reason FROM dba_outstanding_alerts ;

SQL> SELECT reason FROM dba_alert_history

            WHERE upper(reason) like ‘%COMMIT%’

            ORDER BY creation_time desc

            /

Q:   How to clean up your threshold set up?

A:   Do the following statement as sysdba. Set threshold values to NULL.

SQL> BEGIN

            DBMS_SERVER_ALERT .set_threshold (

                        DBMS_SERVER_ALERT .user_commits_sec,

                        NULL,

                        NULL,

                        NULL,

                        NULL,

                        1, 1, ‘SCHOOL’,

                        DBMS_SERVER_ALERT .object_type_system, NULL);

         END;

          /

Q:   How do you disable your ALERT_MYUSER and remove subscriber?

A:

SQL> EXEC dbms_aqadm .disable_db_access(‘ALERT_MYUSER’,’SYSTEM’);

SQL> BEGIN

            dbms_aqadm .remove_subscriber(

            ‘SYS.ALERT_QUE’,AQ$_AGENT(‘ALERT_MYUSER’,’’,0);

          END;

          /

Application tuning

Q:   What is the OPTIMIZER_DYNAMIC_SAMPING setting default?

A:   To enhance Query Optimization, the OPTIMIZER_DYNAMIC_SAMPING is set to 2 by default.

Q:   How do you disable the Automatic PGA Memory Management?

A:   In order to disable the Automatic PGA Memory Management set the parameter to 0.

Q:   How do you gather statistics on dictionary tables in the Oracle 10g Database?

A:   In Oracle Database 10g, you can gather statistics on dictionary tables (both fixed and real) to get the best performance. You use the DBMS_STATS .GATHER_DATABASE_STATS procedure with GATHER_SYS argument set to TRUE or DBMS_STATS.GATHER_DICTIONARY_STATS. To use this, you should have the ANALYZE ANY DICTIONARY system privilege. For example:

SQL> BEGIN

            DBMS_STATS .GATHER_DATABASE_STATS(options=’GATHER AUTO’);

          END;

           /    -- Note: you should use GATHER only if you are using release 8i

Q:   What is the Automatic Tuning Optimizer (ATO)?

A:   It is a SQL automatic tuning optimaizer. When the optimizer is tuning a SQL statement using ATO, it is called Automatic SQL Tuning.

Q:   How do you perform automatic SQL tuning?

A:  

Create a binding variable and then move your query into it.

SQL> VARIABLE my_query VARCHAR2(1000)

SQL> BEGIN

            :my_query := ‘SELECT ename FROM iself.emp WHERE empno = 100;’

         END;

         /

Q:  How do you use the DBMS_SQLTUNE  package to create a tuning task by calling the CREATE_TUNING_TASK  function?

A:   We use the DBMS_SQLTUNE  package to create a tuning task by calling the CREATE_TUNING_TASK  function. This procedure creates an advisor task and sets its corresponding parameters according to the user-provided input arguments. To execute this you need one more binding variable to keep your task name.

SQL> VARIABLE my_task VARCHAR2(100)

SQL> BEGIN

            :my_task := DBMS_SQLTUNE .create_tuning_task (

                        SQL_TEXT      =>             :my_query,

                        BIND_LIST        =>            SQL_BINDS(anydata.ConvertNumber(100)),

                        USER_NAME   =>            ‘ISELF’,

                        SCOPE             =>             ‘COMPREHENSIVE’,

                        TIME_LIMIT       =>            60,

                        TASK_NAME   =>            ‘my_tuning_task’,

                        DESCRIPTION   =>            ‘Query on EMP table …’);

         END;

         /

Q:   How do you use the EXECUTE_TUNING_TASK procedure to start the tuning process?

A:   You need to invoke the EXECUTE_TUNING_TASK procedure to start the tuning process.

SQL> BEGIN

            DBMS_SQLTUNE .execute_tuning_task (TASK_NAME=>:my_task);

         END;

Q:   How do you call the REPORT_TUNING_TASK function to visualize the tuning results?

A:   The following is an example of how to call the REPORT_TUNING_TASK function to visualize the tuning results.

SQL> SQL> SELECT DBMS_SQLTUNE .report_tuning_task

                        (TASK_NAME=>:my_task)

                        FROM dual;

Q:   How do you store a SQL profile in the data dictionary?

A:   When the SQL Tuning Advisor recommends a SQL Profile, then create the SQL Profile by calling the ACCEPT_SQL_PROFILE function, which stores it in the data dictionary. You should have the CREATE ANY SQL PROFILE privilege.

SQL> VARIABLE my_profile VARCHAR2(1000)

SQL> BEGIN

            :my_profile := DBMS_SQLTUNE .accept_sql_profile

                        (TASK_NAME   =>            ’my_tuning_task’);

         END;

         /

SQL> SELECT :my_profile FROM dual;

Database Resource Manager

Q:  How to do you use the DBMS_RESOURCE_MANAGER  package to tell the PMON process to kill sessions that are idle for longer than 600 seconds and kill sessions that are idle for more than 300 seconds and are blocking other sessions. We assumed that you have already defined your plan as ‘MY_DAY_PLAN’ and your group as ‘MY_FIRST_GROUP.’

A:

SQL> BEGIN

            DBMS_RESOURCE_MANAGER .create_plan_directive (

            PLAN                                        =>            ‘MY_DAY_PLAN’,

            GROUP_OR_SUBPLAN            =>            ‘MY_FIRST_GROUP’,

            COMMET                                =>            ‘Limit user idle time’,

            MAX_IDLE_TIME                       =>            600,

            MAX_IDLE_BLOCKER_TIME     =>            300);

         END;

         /

Scheduler

Q:   What is the DBMS_SCHEDULER  package?

A:   Oracle Database 10g provides scheduling capabilities through the database Scheduler . It uses the DBMS_SCHEDULER  package. The Scheduler offers far more functionality than the DBMS_JOB  package. You can create a job class a job class always belongs to the SYS schema. Since the priority of jobs change over a period, now you can also create a window. For example: you can create a window for the month of October that uses the END_OF_YEAR plan and is active every day from 8:00 a.m. to 6:00 p.m. Eastern standard Time (EST).

Q:   How do you monitor a Job using the Database Control page?

A:   Log in to EM Database Control  as the ISELF user. From the Database Control home page click on the Administration tab. In the ‘Scheduler ’ region, click the ‘Jobs’ link.

You should see:

One schedule, called DAILY_PURGE_SCHEDULE by clicking the Schedulers link,

Two windows, called WEEKNIGHT_WINDOW and WEEKEND_WINDOW by clicking the Windows link, and

Two job classes, called DEFUALT_JOB_CLASS , AUTO_TASKS_JOB_CLASS  by clicking the Job Classes link.

Q:   How do you add a Job using the Database Control page?

A:   Click the Create button on the Scheduler  Jobs page; fill out the applicable fields;

Back to the Create Job page; enter location of your job script in the Executable Name field; and then click the Schedule tab.

On the Schedule page, make sure that the immediate radio button and the Repeat field are set to Do Not Repeat.

Q:   How to create a schedule named MY_SCHEDULE owned by ISELF that executes every five seconds.

A:  

SQL> CONNECT iself/schooling

SQL> BEGIN

            DBMS_SCHEDULER .create_schedule (

            SCHEDULE_NAME            =>            ‘MY_SCHEDULE’,

            START_DATE                =>            SYSTIMESTAMP,

            REPEAT_INTERVAL            =>            ‘FREQ=SECONDLY;INERVAL=5’,

            COMMENTS                =>             ‘This is my first created schedule.’);

         END;

         /

Now, you should be able to see it in your Database Control page.

Q:   How to schedule a job that calls your created online-backup every night at 10 p.m.?

A:   You should have been granted CREATE JOB to be able to create a job. Jobs are created as disabled by default. You must enable them explicitly.

SQL> BEGIN

            DBMS_SCHEDULER .create_job (

            JOB_NAME                 =>            ‘ISELF.ONLINE_BACKUP’,

            JOB_TYPE                    =>            ‘EXECUTABLE’,

            JOB_ACTION               =>            ‘/home/my_Nightly_online_backup.sh’,

            START_DATE                =>            TRUNC(SYSDATE+1)+22/24,

            REPEAT_INTERVAL            =>            ‘TRUNC(SYSDATE+1)+22/24’,

            COMMENTS                =>            ‘My nightly online backup’);

        END;

        /

Q:   Assuming that you have a procedure that collects information daily called DAILY_DATA_GATHERING. Now, you should create a problem to call this procedure and create a job to run it daily. How you do that?

A: 

SQL> BEGIN

            DBMS_SCHEDULER .create_program (

            PROGRAM_NAME            =>            ‘DAILY_GATHERING’,

            PROGRAM_ACTION            =>            ‘ISLEF.DAILY_DATA_GATHERING’,

            PROGRAM_TYPE            =>            ‘STORED_PROCEDURE’,

            ENABLED                    =>            TRUE);

         END;

SQL> BEGIN

            DBMS_SCHEDULER .create_job (

            JOB_NAME                 =>            ‘ISELF.DAILY_GATHERING_JOB’,

            PROGRAM_NAME            =>            ‘ISLEF.DAILY_GATHERING’,

            START_DATE                =>            TRUNC(SYSDATE+1)+22/24,

            REPEAT_INTERVAL            =>            ‘TRUNC(SYSDATE+1)+22/24’,

            COMMENTS                =>            ‘Daily Data Gathering Job.’);

        END;

        /

You could also use your created schedule:

SQL> BEGIN

            DBMS_SCHEDULER .create_job (

            JOB_NAME                 =>            ‘ISELF.DAILY_GATHERING_JOB’,

            PROGRAM_NAME            =>            ‘ISLEF.DAILY_GATHERING’,

            SCHEDULE_NAME            =>            ‘MY_SCHEDULE’);

        END;

        /

Tablespace Monitoring

Q:  How an alert will raise or clear based on a tablespace size?

A:   In the Oracle Database 10g, tablespace thresholds are defined in terms of a percentage of the tablespace size. When the threshold crosses their limits, an appropriate alert will raise or clear.

Q:   When do you need to enable row movement on a segment?

A:   Since a shrink operation may cause ROWIDs to change in heap-organized segment, before executing a shrink operation you should enable row movement on a segment.

For example:

SQL> ALTER TABLE emp ENABLE ROW MOVEMENT ;

SQL> ALTER TABLE emp SHRINK SPACE CASCADE ;

Q:   On the USERS tablespace, set a warning threshold of 80% and a critical threshold of 95%.

A:  

SQL> BEGIN

            DBMS_SERVER_ALERT .set_threshold (

            DBMS_SERVER_ALERT .tablespace_pct_full,

            DBMS_SERVER_ALERT .operator_ge, 80,

            DBMS_SERVER_ALERT .operator_ge, 95, 1, 1, NULL,

            DBMS_SERVER_ALERT .object_type_tablespace, ‘USERS’);

         END;

You can use the NULL value to return to the database-wide default values.

Q:   How do you check the database-wide threshold values for the USERS tablespace?

A:  

SQL> SELECT warning_value, critical_value

            FROM dba_thresholds

            WHERE metrics_name = ‘Tablespace Space Usage’ AND

                         object_name = ‘USERS’

            /

Q:   How do you turn off the space-usage tracking for the USER tablespace?

A:

SQL> BEGIN

            DBMS_SERVER_ALERT .set_threshold (

            DBMS_SERVER_ALERT .tablespace_pct_full,

            DBMS_SERVER_ALERT .operator_do_not_check, ‘0’,

            DBMS_SERVER_ALERT .operator_do_not_check, ‘0’, 1, 1, NULL,

            DBMS_SERVER_ALERT .object_type_tablespace, ‘USERS’);

         END;

Q:   How do you reset the database-wide threshold values of the USERS tablespace to the default database values?

A:

SQL> BEGIN

            DBMS_SERVER_ALERT .set_threshold (

            DBMS_SERVER_ALERT .tablespace_pct_full,

            NULL, NULL, NULL, NULL, 1, 1, NULL,

            DBMS_SERVER_ALERT .object_type_tablespace, ‘USERS’);

         END;

Q:   How do you check the status of your threshold?

A:

SQL> SELECT reason, resolution

            FROM dba_alert_history

            WHERE object_name = ‘USERS’;

SQL> SELECT reason, message_level

            FROM dba_outstanding_alerts

            WHERE object_name = ‘USERS’;

Big and small file tablespaces

Q:   What is a BIGFILE  tablespace?

A:   It is the Oracle Database 10g feature. A bigfile tablespace  (BFT ) is a tablespace containing a single file that can have a very large size and on the other hand a smallfile tablespace can contain many data files. The size of a bigfile can reach to 128TB depending on the Oracle block size. An Oracle database can contain both bigfile and smallfile tablespaces. You can change the default tablespace type to BIGFILE  or SMALLFILE.

Q:   How do you set the default tablespace type to BIGFILE ?

A:   To set the default tablespace type to BIGFILE , you can use either CREATE DATABASE or ALTER DATABASE.

Q:   how do you display the default tablespace type?

A:   You use the DATABASE_PROPERTIES  dictionary view to display the default tablespace type for the database:

SQL> SELECT property_value FROM database_properties

            WHERE property_name = ‘DEFAULT_TBS_TYPE’;

Q:    Use the DBA_TABLESPACES  dictionary view to display whether all tablespace is bigfile (YES) or smallfile (NO).

A:

SQL> SELECT tablespace_name, bigfile FROM dba_tablespaces;

Q:   Use the V$TABLESPACE  dynamic view to display whether all tablespace is bigfile (YES) or smallfile (NO).

A:

SQL> SELECT name, bigfile FROM v$tablespace;

Q:   What are the difference between a BIGFILE  rowid and a small file rowid?

A:  Extended ROWID format :

For Smallfile tablespaces is Object# - File# - Block# - Row#

For Bigfile tablespaces is Object# - Block# - Row#

Q:   Create a temporary tablespace group that it consists of only temporary tablespaces.

A:

SQL> CREATE TEMPORARY TABLESPACE mytemp1

            TEMPFILE ‘temp_01.dbf’ SIZE 500M

            TABLESPACE GROUP mygroup;

The mygroup group has one more temporary tablespace in its groups. If you do not want to assign any temporary tablespace to a group do the following:

SQL> CREATE TEMPORARY TABLESPACE mytemp2

            TEMPFILE ‘temp_02.dbf’ SIZE 500M

            TABLESPACE GROUP ‘’;

Q:   Use the DBA_TABLESPACE_GROUPS  view to display all tablespace associated to their groups.

A:

SQL> SELECT tablespace, group_name FROM dba_tablespace_groups;

Q:   Create a tablespace with a BIGFILE  default tablespace type.

A:

SQL> CREATE BIGFILE  UNDO TABLEPSACE my_big_tbs

            DATAFILE ‘/u01/oradatta/tbs_01.dbf’ SIZE 1G;

Q:   Can you add more datafiles?

A:    If you try to add more datafile to above tablespace, do the following.

SQL> ALTER TABLESPACE my_big_tbs

            ADD DATAFILE ‘/u02/oradata/tbs_02.dbf’ SIZE 100k;

Notice, since a bigfile tablespace  can contain only one data file, your command should fail.

Q:   How do you get a BIGFILE  ROWID?

A:   To get its ROWID, you should use the following database package (DBMS_ROWID).

SQL> SELECT distinct DBMS_ROWID.ROWID_RELATIVE_FNO (ROWID,’BIGFILE ’)

            FROM test_rowid;

General Storage  Enhancements

Q:   What is System Auxiliary Tablespace in the Oracle 10g Database?

A:   The Oracle 10g database added one more tablespace (SYSAUX) to help the SYSTEM tablespace. The SYSAUX tablespace  is an auxiliary tablespace to the SYSTEM tablespace. It is a mandatory tablespace and should be created at database creation time. You cannot drop or rename this tablespace.

Q:   What does the SYSAUX tablespace  hold?

A:     

• Text, Ultra Search

• Intermedia, Spatial

• Scheduler

• OLAP

• XML DB

• Workspace Manager

• Data Mining

• Server Manageability Components

• Recovery Catalog

• EM Repository

• Analytical Workspace Object table

• LogMinor, Log Standby, Streems

• Statspack

Q:   How can you monitor the space usage of each occupant inside the SYSAUX tablespace ?

A:   Use the following SQL statement.

SQL> SELECT occupant_name, space_usage_kbytes

            FROM v$sysaux_occupants

            /

Q:   What are the Mandatory attributes of SYSAUX?

A:

• PERMANENT

• READ WRITE

• EXTENT MANAGEMENT LOCAL

• SEGMENT SPACE MANAGEMENT AUTO

Q:   What are its benefits?

A:   It reduces the number of tablespaces to manage. You don’t need to create the TOOLS, OEM_REPOSITROY, DRSYS, CWMLITE, ODM, etc tablespaces.

You reduce the load on the SYSTEM tablespace.

Q:   Can you rename SYSTEM or SYSAUX tablespaces?

A:   Now you can rename tablespace in the Oracle 10g database. You can not rename the SYSTEM and SYSAUX tablespaces. You can rename any permanent or temporary tablespaces. All tablespaces must have their datafiles online. Your database spfile will be updated.

Q:   How do you rename a tablespace?

A:   To rename a tablespace do the following SQL statement.

SQL> ALTER TABLESPACE tools RENAME TO my_tools;

Q:   Can you change the default Permanent Tablespace in the Oracle 10g database?

A:   Now, you can change the default permanent tablespace for non-system users.

Q:   How can you check what your default permanent tablespace is?

A:   Query the following SQL statement.

SQL> SELECT property_value

            FROM database_properties

            WHERE property_name =

                        ‘DEFAULT_PERMANENT_TABLESPACE’

            /

Q:   Change your default tablespace to USERS.

A:   Assuming your default tablespace is SYSTEM, and then you change it to USERS.

SQL> ALTER DATABASE DEFAULT TABLESPACE users;

Q:   How can you copy files without using system operating system commands?

A:   You can use the COPY_FILE procedure in the DBMS_FILE_TRANSFER  package to copy a file from one place to another. You should make sure to create source and destination directories and you have a read access on the source directory and a write access on the destination directory.

Assuming we are going to copy file a1.dbf from location /u01/oradata/school to location /u02/oradata/school.

SQL> CREATE DIRECTORY my_source AS ‘/u01/oradata/school’;

SQL> CREATE DIRECTORY my_destination AS ‘/u02/oradata/school’;

SQL> BEGIN

            DBMS_FILE_TRANSFER .COPY_FILE (

            SOURCE_DIRECTORY_OBJECT => ‘MY_SOURCE’,

            SOURCE_FILE_NAME => ‘a1.dbf’,

            DESTINATION_DIRECTORY_OBJECT => ‘MY_DESTINATION’,

            DESTINATION _FILE_NAME => ‘a1.dbf’);

          END;

            /

Q:   What does the Redo Logfile size advisor  in the Oracle 10g database?

A:   It determines the optional smallest online redo log file size based on the current FAST_START_MTTR_TARGET  setting and the corresponding statistics. To enable the Redo Logfile Size Advisor , you should set the FAST_START_MTTR_TARGET parameter. Note that an online redo log file size is considered optimal if it does not drive incremental check pointing more aggressively than needed by FAST_START_MTTR_TARGET.

Q:   Make the retention period for one day with an interval off “0” which switches off snapshot collection.

A:  

SQ> EXEC dbms_workload_repository .modify_snapshot_settings (1440, 0);  -- 1440 minute or 1 day and “0” switches OFF snapshot collection.

Automatic Storage Management  (ASM )

Q:   What does ASM  provide?

A:   ASM  provides a vertical integration of the file system and the volume manager that is specifically built for Oracle database files.

Q:   What are its key features and benefits?

A:

• Stripes files rather than logical volumes

• Online disk reconfiguration and dynamic rebalancing

• Adjustable rebalancing speed

• Provides redundancy on a file basis

• Supports only Oracle database files

• Custer-aware

• Automatically installed

Q:   Does ASM  have a data dictionary?

A:   ASM  instance does not have a data dictionary and it is restricted to few SQL commands and Dynamic Performance view.

Q:   How do you create a disk group by using ASM ?

A:   The following are examples of creating and deleting disk groups.

Creating a diskgroup:

SQL> CREATE DISKGROUP dgora1 NORMAL REDUNDANCY

            FAILGROUP controller1 DISK

                        ‘/dev/rdsk/c0t0d0s2’ NAME mydisk SIZE 200G FORCE,

                        ‘/dev/rdsk/c0t1d0s2’,

                        ‘/dev/rdsk/c0t2d0s2’

            FAILGROUP controller2 DISK

                        ‘/dev/rdsk/c1t0d0s2’,

                        ‘/dev/rdsk/c1t1d0s2’,

                        ‘/dev/rdsk/c1t2d0s2’;

Q:   How do you delete a disk group by using ASM ?

A:   Dropping a diskgroup:

SQL> DROP DISKGROUP dgora1 INCLUDING CONTENTS;

Q:   How do you add a disk to an existing disk group?

A:   The following are examples of how to add disks to an existing disk group.

SQL> ALTER DISKGROUP dgora1

                        ADD FAILGROUP controller1

                        ‘/dev/rdsk/c0t3d0s2’ NAME a5;

Q:   How do you remove a disk to an existing disk group?

A:   To remove a disk:

SQL> ALTER DISKGROUP dgora1 DROP DISK a5;

Q:   Can you undo the removed disk? How?

A:   Yes. To undo the removed disk do the following SQL statement. This only works if the status of drop is pending or the drop function was not completed yet.

SQL> ALTER DISKGROUP dgora1 UNDROP DISKS;

Q:   How do you display a list of your diskgroups?

A:   To display a list of diskgroups.

SQL> SELECT name FROM v$asm_diskgroup;

Q:   How do you display a list of associated ASM  disks?

A:   To display a list of associated ASM  disks.

SQL> COL name FORMAT a20

SQL> COL failgroup FORMAT a20

SQL> SELECT name, failgroup, bytes_read, bytes_written

            FROM v$asm_disk

            /

Q:   How do you display a list of associated ASM  files?

A:   To display a list of associated ASM  files.

SQL> SELECT group_number, file_number, bytes, type, striped

            FROM v$asm_file

            /

Q:   How do you create a tablespace that uses an ASM  disk group?

A:   To create a tablespace that is stored in the ASM  disk group dgora1.

SQL> CREATE TABLESPACE mytablespace2

            DATAFILE ‘+dgora1’ SIZE 100m

            /

Q:   How do you add one addition disk to your system?

A:   Do the following.

SQL> HOST dd if=/dev/zero of=/u02/oradata/school/diska abs=1024k count=200

SQL> SELECT name, failgroup, bytes_read, bytes_written

            FROM v$asm_disk

            /

SQL> ALTER DISKGROUP dgora1

            ADD DISK ‘/u02/oradata/school/diska’

            /

Execute the following query until you get ‘no rows selected.’

SQL> SELECT operation, est_minutes

            FROM v$asm_operation

            /

Again, display a list of associated ASM  disks.

SQL> SELECT name, failgroup, bytes_read, bytes_written

            FROM v$asm_disk

            /

Now, you should see one more disk was added to disk group.

Security VPD

Q:   What is VPD  in the Oracle 10g Database?

A:   In the Oracle 10g database, there is a feature called Virtual Private Database (VPD ). It enables you to build applications that enforce your security policy. When a user requests a query, the server dynamically modifies the user’s SQL statement, which is not transparent to the user. The modification is based on a WHERE clause returned by a function.

The Oracle 10g database more features that are important to note

Q:   How do you use the V$FAST_START_TRANSACTIONS  view to monitor (in real-time) normal transaction rollback and transaction recovery by SMON?

A: 

SQL> SELECT * FROM v$fast_start_ transactions;

Q:   How do you use the V$FAST_START_SERVERS  view to display historical information about transaction recovery?

SQL> SELECT * FROM v$fast_start_servers;

Q:   How do you use the DBA_ENABLED_TRACES  view to display enabled and disabled trace?

A:

SQL> SELECT * FROM dba_enabled_traces;

Q:   What is case-insensitive sorting in the Oracle 10g?

A:   In the Oracle 10g database, you can use the ALTER SESSION command to change NLS_SORT  for your session to use case-insensitive binary sorting.

Q:   What is Quote Operator q?

A:   Now, you can eliminate previous additional quotation string. See the following example:

SQL> UPDATE customers

            SET comments =

            q’X In this example, ‘X’ is used as the quotation mark delimiter. X’;

            WHERE ID = 100;

SQL> COMMIT;

Q:   What does the UTL_MAIL package?

A:   You can send e-mail to a user. In order to use the package, you should have already run the utlmail.sql and prvtmail.plb scripts located in the $ORACLE_HOME/rdbms/admin directory.

Oracle Grid

Q:   What is the Oracle 10g Database Grid?

A:   Yesterday was Internet and today is Grid. It looks like the technology finds its way to hang on something to grow. Now, there is a committee called the Global Grid Forum (GGF) that is developing standards for Grid computing.

Q:   List some of the most important features of the Oracle 10g Grid.

A:   The following are some of the most important features that enable Grid computing at the Oracle 10g Database level:

• Automatic Storage Management

• Portable Clusterware

• High-Speed InfiniBand Network Support

• Real Application Clusters and automatic workload management

• Resource Manager

• Oracle Streams

• Centralized Management with Enterprise Manager Grid Control

• Oracle Database 10g New self-management feature

• …

Q:   What is OEM 10g?

A:   It is Oracle Enterprise Manager with features that are more new. It can automatically alert you to new critical patches.  You can use the patch wizard to select an interim patch and see if any of your system requires it. It is integrated with a build-in MetaLink connection.

Q:   How do you stop the Oracle Management Server?

A: 

# emctl  stop oms

Q:   How do you start the Oracle Management Server?

A:

# emctl  start oms

Q:   How do you get the status of the Oracle Management Server?

A:   Do the following command:

# emctl  status oms

Q:   How do you start EM Database Control ?

A:

# emctl  start dbconsole

Q:   How do you stop the EM Database Control ?

A:

# emctl  stop dbconsole

Q:   How do you get the status of the EM Database Control ?

A:

# emctl  status dbconsole

Q:   What is the default port for your Web Browser?

A:    The default port is 5500 and you can access it by opening your Web browser and enter the following URL: http://myserver:5500/em

Navigate the Oracle EM Grid Control

Q:   How do you create an Oracle user by using the EM Database Control ?

A:   Go to the EM Database Control  home page as sysdba and click on Administration > Users. On the Users page click on the Create button. You should specify the Name, Enter Password, Confirm Password, Default Tablespace, and Temporary Tablespace fields. Then click on the Roles tab and click on the Modify button; select Resource and DBA from the Available Roles list. Once done, click the Move link and click the OK button. When you are returned to the Create User page, click the OK button.

Q:   How do you export tables from a schema by using the EM Database Control ?

A:   Go to the EM Database Control  home page as sysdba. Click on the Administration tab; click on the Tables link in the Schema region; select your schema in the Schema field in the Search region; and click the Go button. Select your exported tables from the Results region; Select Show Dependencies from the Actions drop-down list; and then click on the Go button in the Results region. On the Export:Review page, click on the Submit Job button.

Q:   How do you import tables from a schema by using the EM Database Control ?

A:   Go to the EM Database Control  home page as sysdba. Click on the Maintenance link; click on the Import from Files link; make sure that the Database Version of Files to Import field is set to 10g or later; and click the Go button. In the Files region, select your directory from where the Data Pump  Import job can retrieve your exported Dump File Set; in the Import Type region, select the Tables option button and make sure the host credentials are correct; then click on the Continue button. Click on the Add button and in the Import:Add Tables page, enter your schema in the Schema field in the Search region; then click on the Go button. Select your tables; click on the Select button and On the Import:Re-Mapping page, click the Add Another Row button in the Re-Map Schema region. Then click the Next button. On the Import:Review page, click on the Submit Job button; on the Status page, click the View Job button; refresh your browser page until the Status field reads Succeeded; and then click the Import link to look at the log file.

Q:   How do you retrieve the latest ADDM  and determine the cause of the problem by using the EM Database Control ?

A:   Go to the EM Database Control  home page as sysdba and click on the Advisor Central link on the Related Links section; select ADDM  in the Advisory Type drop-down list; select Last 24 Hours in the Advisor Runs drop-down list; and when it is done, click on the Go button. Then select the latest ADDM task completed by the ADDM user; click the View Result button; it brings you to the ADDM page and you can see the results for the Performance Analysis; To investigate further, click on the SQL Statements Consuming Significant Database Time Were Found link; it will brings you to the Performance Finding Details page. To tune the statement, click on the Run Advisor Now button; when the analysis finished, you will be directed to the Recommendations for SQL ID: … page.

Q:   How do you shutdown and startup your databases using an initialization parameter file by using the EM Database Control ?

A:   Go to the EM Database Control  home page as sysdba; click the Shutdown button; you should specify host and target database credential; save them and click on the OK button. On the Startup/Shutdown: Confirmation page click the Yes button; on your database page, click the Startup button. Click on the Advanced Options button; make sure that you select your initialization parameter file with its location and then click the OK button.

Q:   How do you check or resize the size of the various SGA buffers using the EM Database Control  and how to enable the Automatic Shared Memory Management  by using the EM Database Control?

A:   Go to the EM Database Control  home page as sysdba; click on the Administration tab; click on the Memory Parameters link in the Instance region; and now you should see the status Automatic Shared Memory Management  (disable or enable), Shared Pool size, Buffer Cache, Large Pool, Java Pool, Total SGA, Maximum SGA size, etc. If the Automatic Shared Memory Management was disabled on the Memory Parameters page, click on the Enable button to enable it.

Q:   How do you look at the corresponding metrics graphic rate by using the EM Database Control ?

A:   Go to the EM Database Control  home page as sysdba; click on the All Metrics link; expand the Throughput link; under this link, click on the User Commits (per second) link; make sure that the View Data field is set to very short period of time (ex: Real Time: 10 Seconds Refresh). Now here, depending on your workload, you should be able to see your graph.

Q:   How do you find a high load SQL statement and fix it by looking at an ADDM  report analysis during the problem by using the EM Database Control ?

A:   Go to the EM Database Control  home page as sysdba.

If the time corresponding to the problem corresponds with the latest ADDM , then you should find the link corresponding to the correct performance analysis directly in the Diagnostic Summary region of the EM Database Control  home page. If not, then go to the Advisor Central page and search for the correct ADDM task. To fix your problem, click the finding with the highest impact on the database time on the corresponding ADDM page. It should correspond to a SQL Tuning recommendation. On the Performance Finding Details page, you see the high-load SQL statement; click on the Run Advisor Now button for the highest high-load SQL statement detected. Once was done, you get the details of the corresponding recommendations. You can also click on the Original Explain Plan button to see the original plan. If you have a proposed SQL command, click on the Implement button after selecting the appropriate SQL command from the Recommendations table.

Q:   How do you determine the most important wait category from the Sessions: Waiting and Working graph by using the EM Database Control ?

A:   Go to the EM Database Control  home page as sysdba; click on the Performance tab; if the period for which you want to observe your database is on the Sessions: Waiting and Working graph use the current graph. If the period is no there, select the Historical value from the View Data drop-down list. On the Performance page click on the User I/O category in the graph’s legend. Select the top SQL statement and you should see the SQL Details page. Click on the Execution History tab to see what isgoing on to the statement. Shorten the Seconds Per Execution option button to get a better understanding of the graph.

Q:   How do you use the SQL Access Advisor  to generate recommendations for a SQL tuning set by using the EM Database Control ?

A:   Go to the Database Control home page as sysdba; click on the Advisor Central link; click on the SQL Access Advisor  link; then select the Import Workload from SQL Repository option button; set the SQL Tuning Set field to your SQL tuning set; and click the Next button. On this page, click on the Both Indexes and Materialized Views and Comprehensive Mode buttons; click on the Show Advanced Options link and make sure your options are set and then click the Next button. On the SQL Access Advisor: Schedule page, select Standard in the Schedule Type file; on the Review page, click the Submit button. Refresh the page until you get the COMPLETED status. Now, select your SQL Access Advisor task and click the View Result button.

Q:   How do you create a job and schedule it to run by using the EM Database Control ?

A:   Go to the Database Control home page as sysdba; click on the Administration tab; in the Scheduler  section, click on the Jobs link; on this page, click on the Create button; on the page, enter a job name the Name field; make sure the set the Logging Level (RUNS), Job Class (DEFAULT_JOB_CLASS), Auto Drop (FALSE), and the Restartable (FALSE). In the Command section, click the Change Command Type button; on the Select Command Option, select the In-line Program: Executable radio button; and the click the OK button. On the Create Job page, enter your shell executable job in the Executable Name field and click the Schedule tab. On this page, select your schedule option and click OK.

Q:   How do you verify that your schedule was created by using the EM Database Control ?

A:   Go to the Database Control home page as sysdba; click on the Administration tab; click the Schedules link on the Scheduler  region.

Q:   How do you change the Tablespace Space Usage thresholds of a tablespace by using the EM Database Control ?

A:   Go to the Database Control home page as sysdba; click on the Administration tab; click on the Tablespaces link; select your tablespace; select Edit > Thresholds; select Specify Thresholds, by percent used; now specify the Warning(%) and Critical (%) fields; and then click the Apply button.

Q:   How do you run the Segment Advisor  for a tablespace by using the EM Database Control ?

A:   Go to the Database Control home page as sysdba; click on the Administration tab; click on the Tablespace link; select your tablespace; select Run Segment Advisor  from the Action field; click the Go button; check that the Comprehensive mode is selected; click the Continue button; check all the options on the Segment Advisor: Schedule, and Options pages. On the Review page, click the Submit button and click refresh until you see COMPLETED. Select your task and click the View Result button to go to the Segment Advisor Recommendations page. Accept all recommendation and then click the Schedule Implementation button.

Q:   How do you use the Undo Advisor to get recommendations to size your UNDO tablespace  by using the EM Database Control ?

A:   Go to the Database Control home page as sysdba; click on the Administration tab; click on the UNDO Management link; on this page change the Analysis Time Period field to Last One Hour and click the Update Analysis button; on the UNDO Management page, you should see Oracle 10g recommendation; click the UNDO Advisor  button to get more info. You can look at the Required Tablespace Size by Undo Retention Length graph. If you change the New Undo Retention field for example you will see the impact on your undo tablespace size. On the UNDO Management page, click the Edit Undo Tablespace button. Change the size or add datafile and click the Continue button. After you are back to the Edit Tablespace page click the Apply button.

Q:   How do you change the size of flash recovery area by using the EM Database Control ?

A:   Go to the Database Control home page as sysdba; click on the Maintenance tab; click on the Configure Recovery Settings link; in the Flash Recovery Area  Size field, you can enter a value that you want to change and then click on the Apply button.

Q:   How do you backup your whole database to tape by using the EM Database Control ?

A:   Go to the Database Control home page as sysdba; click on the Maintenance tab; click on the Schedule backup link; select Customized from the Backup Strategy drop-down list; select Whole Database; make sure that you enter your host credentials and click the Next button; on the Options page, click NEXT; on the Setting page, select Tape, then NEXT; on the Schedule page, click NEXT; on the Review page, click Submit Job. Now you should be able to view your job by clicking on the View Job button. Once the job is done, click the Backup link on the Execution page. You see what you want to see.

Q:   How do you use the flashback feature to recover a dropped table by using the EM Database Control ?

A:   Let assume that still your table is in the Recycle Bin area. Go to the Recycle Bin page; select your object; and click the Flashback  Drop button. You will be prompted to the Perform Recovery: Rename page to change the original name if you wish. Leave the original name, and click NEXT. On the Review page, click the Submit button and click OK on the Confirmation page. Now you should see the Recycle Bin page and your object should have been disappeared.

Q:   How do you determine the Redo Log File size using the Sizing Advice by using the EM Database Control ?

A:   Go to the Database Control home page as sysdba; click on the Administration tab; click on the Redo Log Groups link; on this page you can see the redo log group size; select Sizing Advice in the Actions drop-down list and click the Go button. Now, you should see the recommended optimal redo log file size in the Update Message region of the Redo Log Groups page.