Interview Questions.

Top 100+ Database Administration Interview Questions And Answers

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Top 100+ Database Administration Interview Questions And Answers

Question 1. What Is A Dba?

Answer :

A DBA is a Database Administrator, and this is the most common job which you find a database expert doing. There are Development DBAs and Production DBAs.
A Development DBA commonly works intently with a group of developers and receives greater involved in layout decisions, giving recommendation on performance and writing properly SQL.
That can be enjoyable at a human stage because you're a part of a group and also you share the delight of the groups accomplishments.
A Production DBA (on the other hand) is liable for maintaining Databases inside an employer, so it is a very hard and demanding job. He or she, often gets concerned when all of the layout decisions have been made, and has absolutely to maintain matters up and strolling.
Therefore, of direction, it is also a rewarding activity, each financially and in terms of task pride. But it's miles a greater “lonely” job than being a Development DBA.

Question 2. What Is The Maximum No Of Chars The Parameter Can Store?

Answer :

The maximum no of chars the parameter can save is handiest legitimate for char parameters, which can be as much as 64K. No parameters default to 23 Bytes and Date parameter default to 7 Bytes.

Sybase Interview Questions
Question three. How Do You Reference A Parameter Indirectly?

Answer :

To not directly reference a parameter use the NAME IN, COPY ‘constructed-ins to circuitously set and reference the parameters fee’ Example name_in (’capital parameter my param’), Copy (’XXXX’,’Parameter my_param’)

Question four. If Two Groups Are Not Linked In The Data Model Editor, What Is The Hierarchy Between Them?

Answer :

Two organization this is above are the left maximum rank better than the group that is to proper or below it.

MongoDB Tutorial
Question five. Explain About Horizontal, Vertical Tool Bar Canvas Views?

Answer :

Tool bar canvas perspectives are used to create device bars for man or woman windows. 
Horizontal tool bars are display on the top of a window, just under its menu bar. 
Vertical Tool bars are displayed along the left side of a window
SSRS(SQL Server Reporting Services) Interview Questions
Question 6. What Is The Purpose Of The Product Order Option In The Column Property Sheet?

Answer :

To specify the order of person institution assessment in a cross products.

Question 7. What Is The Use Of Image_zoom Built-in?

Answer :

To control pics in picture items.

Oracle Data Integrator (ODI) Interview Questions
Question eight. Is It Possible To Insert Comments Into Sql Statements Return In The Data Model Editor?

Answer :

Yes it's miles viable to insert feedback into sq. Statements go back in the facts version editor

Question 9. What Are The Options Available To Refresh Snapshots?

Answer :

COMPLETE – Tables are absolutely regenerated the usage of the snapshots question and the grasp tables each time the image referenced.
FAST – If easy snapshot used then a photograph log may be used to send the adjustments to the photo tables.
FORCE – Default fee. If possible it performs a FAST refresh; Otherwise it will perform a whole refresh.

Oracle RAC/ASM Interview Questions
Question 10. What Is A Snapshot Log?

Answer :

A snapshot log is a table inside the master database this is associated with the grasp table. ORACLE makes use of a picture log to tune the rows that have been up to date within the master table. Snapshot logs are used in updating the snapshots based at the master desk.

Question eleven. What Is The Difference Between The Sql*loader And Import Utilities?

Answer :

These two Oracle utilities are used for loading information into the database. The distinction is that the import software is based on the statistics being produced by way of some other Oracle utility EXPORT even as the SQL*Loader application allows facts to be loaded that has been produced with the aid of other utilities from one of a kind data assets simply so lengthy as it conforms to ASCII formatted or delimited files.

Hadoop Administration Interview Questions
Question 12. How Can You Enable A Trace For A Session?

Answer :

Use the DBMS_SESSION.SET_SQL_TRACE or
Use ALTER SESSION SET SQL_TRACE = TRUE;

 

Sybase Interview Questions
Question thirteen. What Are The Different Modes Of Mounting A Database With The Parallel Server?

Answer :

Exclusive Mode If the primary example that mounts a database does so in distinct mode, handiest that Instance can mount the database. Parallel Mode If the first example that mounts a database is started in parallel mode, other times that are began in parallel mode also can mount the database.

Question 14. What Are The Advantages Of Operating A Database In Archivelog Mode Over Operating It In No Archivelog Mode?

Answer :

Complete database recovery from disk failure is possible simplest in ARCHIVELOG mode. Online database backup is possible handiest in ARCHIVELOG mode.

Question 15. What Are The Referential Actions Supported By Foreign Key Integrity Constraint?

Answer :

UPDATE and DELETE Restrict – A referential integrity rule that disallows the update or deletion of referenced records.
DELETE Cascade – When a referenced row is deleted all related established rows are deleted.

 

Oracle GoldenGate Interview Questions
Question sixteen. Compare And Contrast Truncate And Delete For A Table. ?

Answer :

Both the truncate and delete command have the desired outcome of getting rid of all the rows in a desk. The difference between the 2 is that the truncate command is a DDL operation and just movements the high water mark and produces a now rollback. The delete command, then again, is a DML operation, with a view to produce a rollback and thus take longer to finish.

Question 17. Give The Two Types Of Tables Involved In Producing A Star Schema And The Type Of Data They Hold.

Answer :

Fact tables and dimension tables. A reality desk carries measurements while measurement tables will contain statistics so one can help describe the reality tables.

MongoDB Interview Questions
Question 18. What Is A Segment?

Answer :

A section is a hard and fast of extents allocated for a sure logical shape.

SSRS(SQL Server Reporting Services) Interview Questions
Question 19. A Table Is Classified As A Parent Table And You Want To Drop And Re-create It. How Would You Do This Without Affecting The Children Tables?

Answer :

Disable the foreign key constraint to the determine, drop the table, re-create the table, permit the foreign key constraint.

Question 20. Explain The Difference Between $oracle_home And $oracle_base.

Answer :

ORACLE_BASE is the root directory for oracle. ORACLE_HOME located under ORACLE_BASE is wherein the oracle merchandise reside.

Oracle Data Guard Interview Questions
Question 21. Explain The Use Of Setting Global_names Equal To True.?

Answer :

Setting GLOBAL_NAMES dictates how you might connect with a database. This variable is both TRUE or FALSE and if it's far set to TRUE it enforces database hyperlinks to have the equal call because the far flung database to which they're linking.

Question 22. Explain The Difference Between A Function, Procedure And Package?

Answer :

A function and system are the equal in that they're supposed to be a group of PL/SQL code that contains a single task. While a method does now not have to go back any values to the calling software, a feature will go back a single value. A bundle on the other hand is a collection of functions and processes which are grouped together based on their commonality to a enterprise characteristic or application.

Question 23. Explain The Use Of Table Functions?

Answer :

Table capabilities are designed to go back a hard and fast of rows thru PL/SQL common sense but are supposed to be used as a ordinary table or view in a SQL announcement. They also are used to pipeline information in an ETL process.

Sql Server Dba Interview Questions
Question 24. Name Three Advisory Statistics You Can Collect?

Answer :

Buffer Cache Advice
Segment Level Statistics
Timed Statistics
Oracle Data Integrator (ODI) Interview Questions
Question 25. Explain Materialized Views And How They Are Used?

Answer :

Materialized views are gadgets which might be reduced units of statistics which have been summarized, grouped, or aggregated from base tables. They are commonly used in statistics warehouse or selection aid systems.

Question 26. What Does A Control File Contain?

Answer :

A Control document facts the physical structure of the database. It incorporates the following facts. Database Name Names and locations of a database’s files and redolog files. Time stamp of database introduction.

Database Optimization Interview Questions
Question 27. Describe What Redo Logs Are?

Answer :

Redo logs are logical and bodily structures which might be designed to hold all of the modifications made to a database and are intended to aid inside the restoration of a database.

Oracle RAC/ASM Interview Questions
Question 28. What Does Coalescing A Tablespace Do?

Answer :

Coalescing is best legitimate for dictionary-managed tablespaces and de-fragments area via combining neighboring unfastened extents into huge single extents.

Question 29. What Is The Difference Between A Temporary Tablespace And A Permanent Tablespace?

Answer :

A brief tablespace is used for brief objects together with type systems whilst permanent tablespaces are used to store the ones objects intended for use as the proper items of the database.

Oracle Apps DBA Interview Questions
Question 30. What Is Distributed Database?

Answer :

A disbursed database is a network of databases managed through multiple database servers that looks to a person as unmarried logical database. The facts of all databases within the allotted database may be simultaneously accessed and modified.

Question 31. Explain The Difference Between Archivelog Mode And Noarchivelog Mode And The Benefits And Disadvantages To Each?

Answer :

ARCHIVELOG mode is a mode that you may positioned the database in for creating a backup of all transactions which have happened inside the database so that you can recover to any factor in time. NOARCHIVELOG mode is basically the absence of ARCHIVELOG mode and has the disadvantage of now not being able to recover to any point in time. NOARCHIVELOG mode does have the benefit of now not having to jot down transactions to an archive log and accordingly will increase the performance of the database slightly.

Question 32. Explain The Use Of Setting Global_names Equal To True?

Answer :

Setting GLOBAL_NAMES dictates how you may connect to a database. This variable is either TRUE or FALSE and if it is set to TRUE it enforces database links to have the equal call because the remote database to which they're linking.

Question 33. Explain What Partitioning Is And What Its Benefit Is?

Answer :

Partitioning is a method of taking big tables and indexes and splitting them into smaller, greater possible portions.

Hadoop Administration Interview Questions
Question 34. What Are The Basic Element Of Base Configuration Of An Oracle Database?

Answer :

It consists of one or more statistics files. One or extra manipulate files. Two or greater redo log documents. The Database includes multiple users/schemas one or more rollback segments one or more tablespaces Data dictionary tables User items (table, indexes, perspectives etc.,) The server that access the database consists of SGA (Database buffer, Dictionary Cache Buffers, Redo log buffers, Shared SQL pool) SMON (System MONito) PMON (Process MONitor) LGWR (LoG Write) DBWR (Data Base Write) ARCH (ARCHiver) CKPT (Check Point) RECO Dispatcher User Process with associated PGS

Question 35. What Is Database Clusters?

Answer :

Group of tables physically stored collectively because they percentage commonplace columns and are regularly used collectively is known as Cluster.

Question 36. What Is An Index? How It Is Implemented In Oracle Database?

Answer :

An index is a database shape used by the server to have direct access of a row in a table. An index is routinely created when a unique of number one key constraint clause is laid out in create desk command (Ver 7.0)

Oracle GoldenGate Interview Questions
Question 37. What Is A Database Instance?

Answer :

A database example (Server) is a fixed of memory shape and historical past procedures that get right of entry to a set of database files. The technique may be shared with the aid of all users. The memory shape which might be used to keep maximum queried facts from database. This enables up to improve database overall performance through decreasing the amount of I/O finished against facts report.

Question 38. What Is The Use Of Analyze Command?

Answer :

–To perform such a feature on an index, table, or cluster
– To accumulate information about object used by the optimizer and keep them inside the statistics dictionary.
– To delete facts approximately the item utilized by item from the facts dictionary.
– To validate the structure of the object.
– To perceive migrated and chained rows off the desk or cluster.

Question 39. What Is Default Tablespace?

Answer :

The Tablespace to include schema gadgets created with out specifying a tablespace name.

Question forty. What Are The System Resources That Can Be Controlled Through Profile?

Answer :

The wide variety of concurrent classes the user can set up the CPU processing time to be had to the consumer’s session the CPU processing time available to a unmarried name to ORACLE made via a SQL assertion the quantity of logical I/O available to the consumer’s session the amount of logical I/O to be had to a unmarried name to ORACLE made by using a SQL announcement the allowed quantity of idle time for the user’s consultation the allowed quantity of connect time for the consumer’s consultation.

MongoDB Interview Questions
Question forty one. What Is Tablespace Quota?

Answer :

The collective quantity of disk space available to the gadgets in a schema on a specific tablespace.

Question 42. What Are The Different Levels Of Auditing?

Answer :

Statement Auditing
Privilege Auditing 
 Object Auditing
Oracle Data Guard Interview Questions
Question 43. What Is Statement Auditing?

Answer :

Statement auditing is the auditing of the effective machine privileges without regard to specifically named gadgets

Question 44. What Are The Database Administrators Utilities Available?

Answer :

SQL * DBA – This permits DBA to reveal and control an ORACLE database.
SQL * Loader – It loads facts from standard working system files (Flat files) into ORACLE database tables. Export (EXP) and Import (imp) utilities can help you flow current facts in ORACLE format to and from ORACLE database.

Question forty five. How Can You Enable Automatic Archiving?

Answer :

Shut the database Backup the database Modify/Include LOG_ARCHIVE_START_TRUE in init.Ora report. Start up the database.




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