Interview Questions.

Q1. List The Log Miner Procedures?

Log miner strategies are given as follows:

ADD_LOGFILE – Adds a record to the existing or newly created list of archive files to system.

START_LOGMNR – Initializes the LogMiner application.

END_LOGMNR – Finishes a LogMiner session.

The following  capabilities also can be used with log miners:

MINE_VALUE (characteristic) – Returns undo or redo fee for the column certain as parameter based at the statistics gift within the v$logmnr_contents view.

COLUMN_PRESENT ( function) – Verifies whether undo or redo values is present within the v$logmnr _contents view for the column unique as parameter.

Q2. What Is The Use Of Recording Information About Current Session?

The records is beneficial for tracing. You can get patron records, module, or movement records from exceptional module of the application.

At runtime, you could query special overall performance perspectives to discover the action executed by way of utility at that specific time.

Q3. When Does An Alert Gets Signaled?

Alerts are traction based totally. Whenever, a traction inflicting event of hobby commits, the alert is signaled.

Q4. How Can You Schedule A Job In Database?

You can use the dbms_scheduler bundle to create and time table a database task.

Q5. How Can You Implement Fine Grained Auditing?

Oracle has supplied a bundle referred to as dbms_fga to put in force great grained auditing.

It incorporates the subsequent strategies:

Add_policy

Drop_policy

Enable_policy

Disable_policy

Q6. What Is The Commonly Used Procedure Of The Dbms_lock Package?

The dbms_lock.Sleep technique is the maximum commonly used procedure from the dbms_lock bundle.

It suspends a consultation for distinctive time c programming language.

It takes a parameter in seconds.

The smallest increment can be entered in hundred of a 2d.

Q7. How Can Retrieve Object Definitions From Data Dictionary?

You can use the dbms_metadata package to retrieve item definitions from facts dictionary with the aid of specifying the following:

Types of item, such as tables, indexes or tactics.

Optional selection standards, consisting of owner or name.

Parse gadgets (attributes of the returned gadgets that are to be parsed and lower back one at a time)

Optional trformations on the output in Extensible Markup Language (XML) or Data Definition Language (DDL) format.

Q8. What Are The Benefits Of Flashback Feature?

Flashback characteristic affords the following advantages:

Flashback Database – you may use this selection to flashback database to some extent in beyond in preference to restoring from backup and recovering to the unique point.

Flashback Standby Database – You can use this selection to flashback standby database to a time previous to factor of failure.

Flashback Re-instantiation – You do no longer want to re instantiate database following a failover the use of this feature.

Flashback Drop – You can repair dropped tables the usage of this feature.

Flashback Table – You can use this option to flashback table to a selected point.

Flashback Row History – This function offers you capability to view the modifications in one or extra rows.

Flashback Traction History – You can use this selection to diagnose issues, carry out analysis and audit tractions.

Q9. Which Procedures Can You Use To Encrypt And Decrypt Data In Different Formats?

Following strategies can be used to encrypt or decrypt statistics in one-of-a-kind codecs:

DESEncrypt – Generates the encrypted form of the enter statistics.

DESDecrypt – Generates the decrypted shape of the enter data.

DES3Encrypt – Generates the encrypted shape of the enter records by means of passing it via the triple DES encryption algorithm.

DES3Decrypt – Generates the decrypted shape of the input information.

Q10. How Does Oracle Facilitate Communication Between Different Sessions?

You can use the dbms_pipe bundle to talk between different sessions.

The facts send through pipe is stored in SGA and is lost whilst instance is close down.

Q11. How Do You Resize A Datafile?

You can resize a datafile by way of using the ALTER DATABASE DATAFILE <file_name> RESIZE; announcement.

Q12. How Can You Record Information About Current Session?

Oracle presents a bundle called dbms_application_info. This package can be used to set statistics approximately contemporary consultation.

Q13. How Can A Session Indicate Its Interest In Receiving Alerts?

A consultation can register itself for a selected form of alert or a indicators by way of using the register manner. Such classes are called ready session.

Q14. What Functionality Does Oracle Provide To Secure Sensitive Information?

You can use the dbms_obfuscation_toolkit bundle to encrypt sensitive data.

The Data Encryption Standard (DES) or triples DES algorithm may be used to encrypt the records.

Q15. How Can You Create A User Defined Lock?

The dbms_lock package deal may be used to create person defined locks.

Q16. What Is A User Defined Lock?

Oracle manages database resources via locking mechanism.

These locks are generally controlled through the machine and are launched on devote or rollback of a traction.

However, Oracle has provided this functionality to the users if you want to create person defined locks.

These locks are much like system created locks in functionality but are not launched automatically whilst traction commits or rollbacks. Therefore, a user must be extremely careful even as the use of person defined locks.

Q17. How Can You Get The Information Processed By Log Miner Procedures?

The information processed via log miner is saved within the v$logmnr_contents view.

You can be use the dbms_logmnr.Mine_value and dbms_logmnr.Column_present tactics with the statistics in the v$logmnr_contents view to check the information.

Q18. How Can You Generate Profile Of Pl/square Applications To Identify Performance Bottlenecks?

You can use the dbms_profiler package to gather and store profile statistics about a PL/SQL application.

Q19. How Can You Create An Advanced Queuing (aq)?

Oracle presents the dbms_aqadm bundle to create a complicated queue. This package deal may be used to create, adjust, and drop AQ.

The technique that offers these functions are given as follows:

Create_queue_table

Alter_queue_table

Drop_queue_table

Create_queue

Alter_queue

Drop_queue

Start_queue

Stop_queue

Q20. How Would You Determine Who Has Added A Row To A Table?

This may be determined by way of the use of the great grained auditing characteristic for the table.

Q21. Suppose You Want To Audit Specific Activities On Sensitive Data. How Can You Achieve That?

You can use the quality grained auditing features of Oracle.

Q22. What Procedures Can You Use To Register With An Aq?

The consumer of an AQ is known as a subscriber, which can be brought through the add_subscriber process.

It may be altered the usage of the alter_subscriber process and removed the usage of the drop_subscriber system of the dbms_aqadm package.

Oracle additionally provides procedures to time table propagation of message in an AQ.

This technique is called schedule_propagation.

It may be unscheduled the use of the unscheduled_propagation system.

Q23. What Do You Understand By Flashback Feature Of Oracle?

Flashback feature permits you to use a flashback version of the database, that is, you can query the database from a kingdom within the beyond primarily based on a particular System Change Number (SCN) or time in the beyond.

Q24. How Can You Initialize Log Miner?

You can use the DBMS_LOGMNR.START_LOGMNR process to initialize the log miner.

Q25. Name Some Of The Procedures Available In The Dbms_application_info Package?

The processes available in the dbms_application_info bundle are set_module, sect_action, read_module, set_client_info, read_client_info and set set_session_longtops.

Q26. How Can You Enable Flashback Feature?

Oracle provides the dbms_flashback package to use flashback characteristic.

The package has the subsequent methods to facilitate this option:

Enable_at_time

Enable_at_system_change_number

Get_system_change_number

Disable

Q27. Who Owns The Operating System Files Created By The Utl_file Package?

The operating system documents generated through utl_file are owned with the aid of operating machine consumer Oracle.

Q28. Can You Redefine A Table Online?

Yes, you may use the dbms_redefinition bundle to redefine a desk on line.

Q29. How Can You Communicate With Operating System Files From Oracle?

You can use the utl_file package to talk with working gadget documents from PL/SQL code.

This package offers more than one functions to open, study, write and near the working gadget documents.

Q30. How Can You Find Out If A Table Can Be Redefined?

You can use the dbms_redefinition.Can_redef_table procedure to determine if a desk may be redefined.

Q31. How Can You Get Actual Data Change Values From Previous Tractions In Oracle?

Oracle affords a feature referred to as log minner, which may be used to view data changes from previous tractions.

Q32. How Can You Grant Privileges On Aq To Other Users?

You cannot supply privileges on AQ by means of the use of grant assertion similar to different Oracle objects.

Grant_system_privilege – Grants AQ device privileges

revoke_ system_privilege – Revokes AQ machine privileges

grant_queue_privilege – Grants privileges on AQ

revoke_queue_privilege – Revokes privileges on AQ.

Q33. Does Oracle Provide Any Package To Deal With Materialized Views?

You can use the dbms_mview package deal to address materialized views. It is likewise referred to as dbms_snapshot.

Some of the strategies furnished through the dbms_mview applications are as given follows:

BEGIN_TABLE_REORGANIZATION – Performs a manner to maintain materialized view statistics wanted for refresh.

END_TABLE_REORGANIZATION – Ensures that the materialized view facts for the grasp desk is valid and that the grasp view or potential materialized view.

EXPLAIN_MVIEW – Explains what's possible with a materialized view or capability materialized views.

EXPLAIN_REWRITE – Explains why a query failed to rewrite.

Q34. Does Oracle Support Asynchronous Notification?

Oracle supports asynchronous notification using the dbms_alert package deal.

Q35. How Can You Manage Optimizer Statistics?

You can manage optimizer information thru the dbms_stats package.

This package deal offers multiple functions or approaches to accumulate, alter and eliminate facts.

Statistics stored inside the dictionary have an impact at the price primarily based optimizer. You also can use the dbms_stats manner to collect information in parallel.

Q36. How Can You Process Messages In Order Asynchronously?

Oracle provides a package deal called dbms_aq bundle to queue the messages, which may be consumed via every other consultation or software in order.

Q37. Explain The Major Functions Provided By The Dbms_stats Procedure?

The dbms_stats method plays the following standard capabilities:

Set or get statistics using the set_xxx and get_xxx subprograms.

Trfer information the use of the export_xxx and import_xxx subprograms.

Gather optimizer records the use of the gather_xxx subprograms.

Q38. List Some Of The Procedures Provided By The Dbms_aq Package?

Some of the tactics supplied by means of the dbms_aq package deal are enqueue, dequeue, check in and unregister.

Q39. What Do You Understand By Fine Grained Auditing?

Fine grained auditing may be used to put in force auditing at a low degree of granularity.

It lets in you to audit a traction whilst a selected column or row is modified.