Databases Interview Questions, Answers for Freshers and Experienced asked in various Company Job Interviews

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DB Architecture (141)
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DB Development (113)
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Database Management (1411)
Databases AllOther (288)

Databases Interview Questions

Questions Answers Views Company eMail

What is the difference between truncate and delete? How would a full table scan behave after?

550

What is difference between co-related sub query and nested sub query?

567

What is oracle full backup?

570

What is pga_aggregate_target?

571

A dba had to remove some archivelogs to free up space in filesystem. Nowwhen the rman job starts to backup archivelogs, it complains about missing archivelogs thatwere deleted by dba. To resolve the issue and continue backing up remainder of archivelogs,which rman command can be used so it wo not complain about missing archivelogs.

603

What are the tradeoffs between many vs few indexes? When would you want to have many, and when would it be better to have fewer?

627

If you had a tablespace, test_tablespace, which consists of three files:test01.dbf, test02.dbf, and test03.dbf, and someone accidentally used the unix command"rm" to delete the file test02.dbf, what else would you need in order to recover all the data thatwas present in test_tablespace at the time that test02.dbf was deleted?

566

Tell me about standby database? What should we watch out for?

547

What is the difference between a materialized view (snapshot) fast refresh versus complete refresh? When is one better, and when the other?

615

Explain the wait events in statspack report 'db scattered read', 'db sequential real', 'enqueue'?

659

What are the steps involved in instance recovery in oracle?

550

What is oracle log switch?

619

What does the no logging option do? Why would we use it? Why would we be careful of using it?

550

How do I call oracle stored procedures that take no parameters?

1115

How do I learn what codesets are available in oracle?

1038

Un-Answered Questions { Databases }

What is hot backup (in case of oracle)?

927

Write a query to stop mysql in unix

1051

Why we use join in sql?

966

What is dbcc?

1135

How can I track the changes or identify the latest insert-update-delete from a table?

961

Explain trigger and trigger types?

980

What are the disadvantages of merge replication?

1421

Explain the purpose of %type and %rowtype data types?

928

Is there any difference between primary key and unique with the not null condition?

947

how can you communicate with operating system files from oracle?

1050

Explain the difference between a dynamic and materialized view.

907

What are the different types of triggers in mysql?

963

What is tablix?

162

Explain isolation levels that sql server supports?

1039

Why dbms is used?

941

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