Computer Operator Interview Questions from Database Systems with answers

Interview Questions from Database Systems with answers

Question 1. What are the advantages of DBMS?
Answer :
· Redundancy control
· Restriction for unauthorized access
· Provides multiple user interfaces
· Provides backup and recovery
· Enforces integrity constraints
· Ensure data consistency
· Easy accessibility
· Easy data extraction and data processing due to the use of queries

Question 2. What is RDBMS?
Answer :
RDBMS stands for Relational Database Management Systems. It is used to maintain the data records and indices in tables. RDBMS is the form of DBMS which uses the structure to identify and access data concerning the other piece of data in the database. RDBMS is the system that enables you to perform different operations such as- update, insert, delete, manipulate and administer a relational database with minimal difficulties. Most of the time RDBMS use SQL language because it is easily understandable and is used for often.

Question 3. What do you understand by Data Model?
Answer :
The Data model is specified as a collection of conceptual tools for describing data, data relationships, data semantics and constraints. These models are used to describe the relationship between the entities and their attributes.
There is the number of data models:
· Hierarchical data model
· network model
· relational model
· Entity-Relationship model and so on.

Question 4. Define a Relation Schema and a Relation.
Answer :
A Relation Schema is specified as a set of attributes. It is also known as table schema. It defines what the name of the table is. Relation schema is known as the blueprint with the help of which we can explain that how the data is organized into tables. This blueprint contains no data.

A relation is specified as a set of tuples. A relation is the set of related attributes with identifying key attributes

Question 5. What is the Relationship?
Answer :
The Relationship is defined as an association among two or more entities. There are three type of relationships in DBMS-

One-To-One: Here one record of any object can be related to one record of another object.

One-To-Many (many-to-one): Here one record of any object can be related to many records of other object and vice versa.

Many-to-many: Here more than one records of an object can be related to n number of records of another object.

Question 6. What is normalization?
Answer :
Normalization is a process of analysing the given relation schemas according to their functional dependencies. It is used to minimize redundancy and also used to minimize insertion, deletion and update distractions. Normalization is considered as an essential process as it is used to avoid data redundancy, insertion anomaly, updation anomaly, deletion anomaly.
There most commonly used normal forms are:
· First Normal Form(1NF)
· Second Normal Form(2NF)
· Third Normal Form(3NF)
· Boyce & Codd Normal Form(BCNF)

Question 7. What is the purpose of SQL?
Answer:
SQL stands for Structured Query Language whose main purpose is to interact with the relational databases in the form of inserting and updating/modifying the data in the database.

Question 8. Explain the concepts of a Primary key and Foreign Key.
Answer:
Primary Key is used to uniquely identify the records in a database table while Foreign Key is mainly used to link two or more tables together, as this is a particular field(s) in one of the database tables which are the primary key of some other table.

Question 9. What is Join?
Answer :
An SQL Join is used to combine data from two or more tables, based on a common field between them. For example, consider the following two tables.

Question 10. What is a Trigger?
Answer:
A Trigger is a code that associated with insert, update or delete operations. The code is executed automatically whenever the associated query is executed on a table. Triggers can be useful to maintain integrity in database.

Question 11. Tell some of the most important uses of MS Access?
Answer :
Uses of MS Access:
· MS Access is used as frontend when the backend is product of ODBC compliant.
· MS Access is widely used for small database applications are based on web and hosted on IIS by making use of ASP.NET pages.
· Mainly, it is used by small firms and businesses, specific departments in large organizations and some people for developing applications on desktop for data applications.
· It can be used as RAD while developing standalone applications and prototype.

Question 12. What are queries in MS Access?
Answer :
Queries can be seen as a request used to perform various operations on data such as sort data, insert data, retrieve data, update data, delete data, etc.

Question 13. What are the advantages of MS Access over MS SQL Server?
Answer :
Following are some of the advantages of MS Access over MS SQL Server:
· MS Access is much easier to handle.
· MS Access is more reliable as client can read and write directly into raw data table.
· MS Access is more scalable when number of users are less.
· MS Access is cheaper and more compatible.

Question 14. Explain About Microsoft Access?
Answer :
Microsoft access name has been changed to Microsoft office access. This software incorporates relational database management system which combines GUI (graphical user interface) with Microsoft Jet database engine. It can import and use data from Access, SQL, oracle, etc. This software is used to build application software.

Question 15. Explain About the Various Features Present In Ms Access?
Answer :
Microsoft access has huge benefits for a programmer and end user. Some of the benefits are
· Relative compatibility with SQL and VBA.
· Microsoft SQL server desktop engine is embedded into the Access suite along with getdata base engine which can further help you in programming.
· MS Access allows forms to contain data which is altered as changes are made to the underlying table.
· It has features which support the creation of all objects in the underlying server.

Question 16. State Some of the Uses Of Ms Access?
Answer :
MS Access provides a huge range of functions some of them are
· It is used by small business, departments of large corporations, and by amateurs to create applications on their desktop for data applications.
· Access is very useful for small web based database applications hosted on IIS and using ASP.NET pages.
· It can be used as a RAD for building prototype and Stand alone applications.
· Access can be used as a frontend while the backend can be a ODI3C compliant product.