database schema design questions

Top 10 Database Questions For Interview 

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1.) Define Database ? 

A database is a Logical , consistent and organised collection of Data that can be easily accessed , managed and updated.It is collection of inter-related data.it's mostly consists of the tables and tables include rows and columns.we can also say that Database is collection of meaningful Information.

2.) Define Database Management System ? 

DBMS is a collection of programs that are used to create and maintain a Database.In other words we can also say that DBMS Provides us an interface or tool for performing different operations such as the creation of a database,inserting,deleting and updating data from it.With the Help of DBMS we can easily manage Data Redundancy by using Data Normalization.

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3.) What is Advantages of DBMS ? 

1. Redundancy Control.
2. Restrictions of unauthorized Access.
3. Provide Multiple User Interfaces.
4. Provide Backup and Recovery.
5. Enforces Integrity Constraints.
6. Ensure Data Consistency.
7. Easy Accessibility.
8. Control Transactions Queries.
9. Data Independence.
10. Strong Security.

4.) What is a checkpoint in DBMS ? 

Using Checkpoints , the DBMS can reduce the amount of work to be done during a restart in the event of subsequent crashes.Basically, Checkpoints are used for the recovery of the database after the System Crashes.It's Very Helpful In Transactions Failure.

5.) Describe RDBMS ? 

RDBMS stands for Relational Database Management Systems.It is used to maintain database records and relations among them in Tables. RDBMS is the System that that enables you to perform different operations such as update insert delete manipulate and administer a relational with Minimum Difficulties.

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6.) How Many Types of DBMS Languages ? 

Database Language are used for the UPDATE, MODIFY  and MANIPULATE the Database.

1.) Data Definition Language (DDL) : CREATE, ALTER, DROP, TRUNCATE, RENAME, etc. All these commands are used for updating the data that ? So why they are known as Data Definition Language.

2.) Data Manipulation Language (DML) :  SELECT, UPDATE, INSERT, DELETE, etc. These commands are used for the manipulation of already updated data that's why they are part of Data Manipulation language.

3.) Data Control Language (DCL) : GRANT, REVOKE These commands are used in DCL to control user access on the Database.So both are the Part of DCL.

4.) Transaction Control Language (TCL) : COMMIT, ROLLBACK and SAVEPOINT. These  are the commands that's are used for managing transactions in the Database.


7.) What is Data Model ? 

The Data Models is Specify as a collection of conceptual tools for describing data, data relationships, data semantics and constraints.These models are used to describe the relationships between the Entities and their Attributes.

There are 4 Types of Data Models . . . . . . .       

1. Hierarchical Data Model
2. Network Data Model
3. Relational Model
4. E-R Model

8.) Define Relation Schema and a Relation ? 

A Relation Schema is Specified as a set of attributes. it is also known as table schema. it defines the what name of table is. We can also say that Relational Schema explain us to how data is organized into Tables.Schema is the Basic Structure of Your Database . 

9.) What is a Degree of Relation ? 

The Degree of Relation is a number of attribute of its relation schema. A degree of relation is also known as Cardinality. it is defined as the number of occurrences of an Entity associated with number of occurrences of another Entity.

There are three types of Degree of Relations ........ 

1. one-to-one (1:1) 
2. one-to-many (1:M) 
3. many-to-many (M:M) 

10.) What is the Relationships ? 

The Relationships is defined as an association among two or more Entities. There are three 4 types of Relationships in DBMS . . 

1.) one-to-one : Here one record of any object can be related to one record of another object called one-to-one Relationships. 

For Example : A Male only Married to one Female is called one-to-one Relationships.

2.) one-to-many : Here one record of any object can be related to Many record of another object called one-to-many Relationships. 

For Example : A Customer Has Many Accounts.

3.) Many-to-Many : Here Many record of any object can be related to Many record of another object called many-to-many Relationships. 

For Example : Many Customers Buy Many Products.

4.) Many-to-one : Here Many record of any object can be related to one record of another object called many-to-one Relationships. 

For Example : Many Students Have or Assigned One Project.

These all questions are based on new Exam Pattern of Diploma . 

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Technical Content Writer And Owner Of Justok! Website Amit.......