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

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Database Management (1411)
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Databases Interview Questions

Questions Answers Views Company eMail

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

552

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?

617

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?

552

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

1116

How do I learn what codesets are available in oracle?

1038

Un-Answered Questions { Databases }

What is sql comments?

1074

How can you tell if a tablespace has excessive fragmentation?

599

How to write optimized query in mysql?

989

How do I find duplicates in a single column in sql?

1020

What is pg_catalog in postgres?

921

How many types of table create in ms access?

819

What is right join sql?

964

What are all the common sql functions?

1027

How can you filter the duplicate data while retrieving records from the table?

896

Two tables emp(empid,name,deptid,sal) and dept(deptid,deptname) are there.write a query which displays empname,corresponding deptname also display those employee names who donot belong to any dept.

1895

Can we join 3 tables in mysql?

959

What is system catalog or catalog relation? How is better known as?

848

Explain the difference between a FUNCTION, PROCEDURE and PACKAGE.

2338

When is the explicit cursor used ?

1034

What are transaction and its controls?

1040

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