Knowledge in dbms interview questions and answers

DATABASE MANAGEMENT SYSTEMS(Bachelor of engineering.)

This is the secong part of Database management system unit. where in you can know the flow chart on data charts and also know about the primary key and als the scondary key.

DBMS-Active Database and Event-Condition-Action (ECA)

Active Databases Part 1: Introduction Triggers and rules are developed for data integrity and constraints * Triggers make “passive” database “active” * Database reacts to certain situations *Event Condition Action rule : ¨ on event insert/update/delete. Event-Condition-Action (ECA)

Basic DBMS

DBMS TutorialDBMS Tutorial provides basic and advanced concepts of Database. Our DBMS Tutorial is designed for beginners and professionals both.Database management system is software that is used to manage the database.Our DBMS Tutorial includes all topics of DBMS such as introduction, ER model, keys, relational model, join operation, SQL, functional dependency, transaction, concurrency control, etc.What is DatabaseThe database is a collection of inter-related data which is used to retrieve, insert and delete the data efficiently. It is also used to organize the data in the form of a table, schema, views, and reports, etc.For example: The college Database organizes the data about the admin, staff, students and faculty etc.Using the database, you can easily retrieve, insert, and delete the information.Database Management SystemDatabase management system is a software which is used to manage the database. For example: MySQL, Oracle, etc are a very popular commercial database which is used in different applications.DBMS provides an interface to perform various operations like database creation, storing data in it, updating data, creating a table in the database and a lot more.It provides protection and security to the database. In the case of multiple users, it also maintains data consistency.DBMS allows users the following tasks:Data Definition: It is used for creation, modification, and removal of definition that defines the organization of data in the database.Data Updation: It is used for the insertion, modification, and deletion of the actual data in the database.Data Retrieval: It is used to retrieve the data from the database which can be used by applications for various purposes.User Administration: It is used for registering and monitoring users, maintain data integrity, enforcing data security, dealing with concurrency control, monitoring performance and recovering information corrupted by unexpected failure.Characteristics of DBMSIt uses a digital repository established on a server to store and manage the information.It can provide a clear and logical view of the process that manipulates data.DBMS contains automatic backup and recovery procedures.It contains ACID properties which maintain data in a healthy state in case of failure.It can reduce the complex relationship between data.It is used to support manipulation and processing of data.It is used to provide security of data.It can view the database from different viewpoints according to the requirements of the user.Advantages of DBMSControls database redundancy: It can control data redundancy because it stores all the data in one single database file and that recorded data is placed in the database.Data sharing: In DBMS, the authorized users of an organization can share the data among multiple users.Easily Maintenance: It can be easily maintainable due to the centralized nature of the database system.Reduce time: It reduces development time and maintenance need.Backup: It provides backup and recovery subsystems which create automatic backup of data from hardware and software failures and restores the data if required.multiple user interface: It provides different types of user interfaces like graphical user interfaces, application program interfacesDisadvantages of DBMSCost of Hardware and Software: It requires a high speed of data processor and large memory size to run DBMS software.Size: It occupies a large space of disks and large memory to run them efficiently.Complexity: Database system creates additional complexity and requirements.Higher impact of failure: Failure is highly impacted the database because in most of the organization, all the data stored in a single database and if the database is damaged due to electric failure or database corruption then the data may be lost forever

INTRODUCTION OF DATABASE MANAGEMENT SYSTEM (First semester notes) Chapter-1 (Part-1) Makhanlal chaturvedi national University,Bhopal

(Part-1) IN This, There is a chapter SEVEN of DATABASE MANAGEMENT SYSTEM Subject Part-1 named INTRODUCTION OF DATABASE MANAGEMENT SYSTEM Makhanlal Chaturvedi national journalism and communication University, Bhopal. There is a very important note oF DATABASE MANAGEMENT SYSTEM For BCA first semester Students. Share with your friends and help them to learn Fundamental of Computers. There are Five subjects in BCA first semester .

OPERATION AREA OF DATABASE (First semester notes) Chapter-1 (Part-2) Makhanlal chaturvedi national University,Bhopal

(Part-2) IN This, There is a chapter SEVEN of DATABASE MANAGEMENT SYSTEM Subject Part-2 named INTRODUCTION OF DATABASE MANAGEMENT SYSTEM Makhanlal Chaturvedi national journalism and communication University, Bhopal. There is a very important note oF DATABASE MANAGEMENT SYSTEM For BCA first semester Students. Share with your friends and help them to learn Fundamental of Computers. There are Five subjects in BCA first semester .

PURPOSE OF DATABASE MANAGEMENT SYSTEM

(Part-3) IN This, There is a chapter SEVEN of DATABASE MANAGEMENT SYSTEM Subject Part-3 named INTRODUCTION OF DATABASE MANAGEMENT SYSTEM Makhanlal Chaturvedi national journalism and communication University, Bhopal. There is a very important note oF DATABASE MANAGEMENT SYSTEM For BCA first semester Students. Share with your friends and help them to learn Fundamental of Computers. There are Five subjects in BCA first semester .

INTRODUCTION OF DATABASE IN POINTS (First semester notes) Chapter-1 (Part-4) Makhanlal chaturvedi national University,Bhopal

(Part-4) IN This, There is a chapter SEVEN of DATABASE MANAGEMENT SYSTEM Subject Part-4 named INTRODUCTION OF DATABASE MANAGEMENT SYSTEM Makhanlal Chaturvedi national journalism and communication University, Bhopal. There is a very important note oF DATABASE MANAGEMENT SYSTEM For BCA first semester Students. Share with your friends and help them to learn Fundamental of Computers. There are Five subjects in BCA first semester .

DATA MODEL IN DBMS (First semester notes) Chapter-1 (Part-5) Makhanlal chaturvedi national University,Bhopal

(Part-5) IN This, There is a chapter SEVEN of DATABASE MANAGEMENT SYSTEM Subject Part-5 named INTRODUCTION OF DATABASE MANAGEMENT SYSTEM Makhanlal Chaturvedi national journalism and communication University, Bhopal. There is a very important note oF DATABASE MANAGEMENT SYSTEM For BCA first semester Students. Share with your friends and help them to learn Fundamental of Computers. There are Five subjects in BCA first semester .

E-R DATA MODEL DBMS (First semester notes) Chapter-1 (Part-10) Makhanlal chaturvedi national University,Bhopal

(Part-10) IN This, There is a chapter SEVEN of DATABASE MANAGEMENT SYSTEM Subject Part-10 named INTRODUCTION OF DATABASE MANAGEMENT SYSTEM Makhanlal Chaturvedi national journalism and communication University, Bhopal. There is a very important note oF DATABASE MANAGEMENT SYSTEM For BCA first semester Students. Share with your friends and help them to learn Fundamental of Computers. There are Five subjects in BCA first semester .

Database Management Systems

Database Management System or DBMS in short refers to the technology of storing and retrieving usersí data with utmost efficiency along with appropriate security measures. This tutorial explains the basics of DBMS such as its architecture, data models, data schemas, data independence, E-R model, relation model, relational database design, and storage and file structure and much more.Why to Learn DBMS?Traditionally, data was organized in file formats. DBMS was a new concept then, and all the research was done to make it overcome the deficiencies in traditional style of data management. A modern DBMS has the following characteristics −Real-world entity − A modern DBMS is more realistic and uses real-world entities to design its architecture. It uses the behavior and attributes too. For example, a school database may use students as an entity and their age as an attribute.Relation-based tables − DBMS allows entities and relations among them to form tables. A user can understand the architecture of a database just by looking at the table names.Isolation of data and application − A database system is entirely different than its data. A database is an active entity, whereas data is said to be passive, on which the database works and organizes. DBMS also stores metadata, which is data about data, to ease its own process.Less redundancy − DBMS follows the rules of normalization, which splits a relation when any of its attributes is having redundancy in values. Normalization is a mathematically rich and scientific process that reduces data redundancy.Consistency − Consistency is a state where every relation in a database remains consistent. There exist methods and techniques, which can detect attempt of leaving database in inconsistent state. A DBMS can provide greater consistency as compared to earlier forms of data storing applications like file-processing systems.Query Language − DBMS is equipped with query language, which makes it more efficient to retrieve and manipulate data. A user can apply as many and as different filtering options as required to retrieve a set of data. Traditionally it was not possible where file-processing system was used.

Data Independence of DBMS

A database system normally contains a lot of data in addition to users’ data. For example, it stores data about data, known as metadata, to locate and retrieve data easily. It is rather difficult to modify or update a set of metadata once it is stored in the database. But as a DBMS expands, it needs to change over time to satisfy the requirements of the users. If the entire data is dependent, it would become a tedious and highly complex job.Metadata itself follows a layered architecture, so that when we change data at one layer, it does not affect the data at another level. This data is independent but mapped to each other.Logical Data IndependenceLogical data is data about database, that is, it stores information about how data is managed inside. For example, a table (relation) stored in the database and all its constraints, applied on that relation.Logical data independence is a kind of mechanism, which liberalizes itself from actual data stored on the disk. If we do some changes on table format, it should not change the data residing on the disk.Physical Data IndependenceAll the schemas are logical, and the actual data is stored in bit format on the disk. Physical data independence is the power to change the physical data without impacting the schema or logical data.For example, in case we want to change or upgrade the storage system itself − suppose we want to replace hard-disks with SSD − it should not have any impact on the logical data or schemas.