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

Oracle (3253)
SQL Server (4518)
MS Access (429)
MySQL (1402)

Postgre (483)
Sybase (267)
DB Architecture (141)
DB Administration (291)

DB Development (113)
SQL PLSQL (3330)
MongoDB (502)
IBM Informix (50)

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Apache CouchDB (44)
Firebird (5)

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?

593

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

618

What is oracle full backup?

614

What is pga_aggregate_target?

625

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.

645

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?

673

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?

614

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

583

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

669

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

690

What are the steps involved in instance recovery in oracle?

585

What is oracle log switch?

662

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

589

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

1202

How do I learn what codesets are available in oracle?

1078

Un-Answered Questions { Databases }

How do I grant privileges to a user in mysql phpmyadmin?

998

What is table valued function and scalar valued functions?

1164

Can we commit inside a function in oracle?

1012

Explain sybase sql server?

1005

What is sql in java?

1134

What do you understand by correlated subqueries in dbms?

1018

How to get a create statement for an existing table?

1014

What are date and time data types?

1042

in the physical file layout, where should the transaction log be stored in relation to the data file?

1042

What is a reference table in database?

1082

How to sort the rows in sql.

1122

How are the stats updated in postgresql?

895

Define fragmentation.

937

You get a call from you backup dba while you are on vacation. He has corrupted all of the control files while playing with the alter database backup controlfile command. What do you do?

633

What are the various configuration files that are used by oracle forms?

1073

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