12 Computer -- DBMS Concept

A Database management system(DBMS) is software designed to store, retrieve, define and manage data in a database

The objectives of DBMS are :

1.To provide a storage area for the mass amount of relevant data.

2. To make access to the data easy for the end-user.

3. To allow multiple users to be active at one time.

4.To allow the growth of the database.

5. To eliminate data redundancy (duplication of data).

6.To protect the data from the physical harm and unauthorized access.

Relational data model is the primary data model, which is used widely around the world for the data stroage and processing . The model is simple and it has all the properties and capabilities requried tp process data with stroage efficiency.

Its advantage of relational database model are:

• It is very easy low data redundancy.
• Normalization of the database is possible.
• Rapid processing of database is possible.
• Since one table is linked with another, some common fields and rules implement on...

A data definition language (DDL) is a computer language used to create and modify the structure of database objects in a database. for example create table, alter table are instructions in SQL.

DML iS data manipulation language which is used to manipulate data itself. For example : insert, update, delete are instructions in SQL.

Any two database model with diagram are :

1. Hierarchical Database Model

In a hierarchical database model, records are logically organized into a hierarchy of relationship. A hierarchically structured database is arranged logically in an inverted tree pattern. All record in the hierarchy are called nods. Each nodes is related to the other in a parent-child relationship. Each parent may have one or more child records, each can have one parent.

2 Network database model

Network database model...

Microsoft Access is database management system from Microsoft that combines the relational Access Engines with a graphical user interface and software development tools

The uses of MS Access are:

1.Personal application

2.Small business

3.School

4.The workplaces

5.Programming Development

.

Data normalization is a process to present a database in a normal form to avoid undesirable things such as repetition of infomation, inability to represent infomation, loss of infomation, etc.

The advantage of normalization are:

• It reduces data redundancy .
• It improves faster sorting and index creation.
• It createsa few indexes and nulls.
• It ignores the repetitionof information.
• It improves the performance of a system.
• It avoid and the loss of information. ...

Hierarchical Database Model in which data is stored in the form of records and organized into a tree-like structure, or parent-child structure, in which in parent node can have many child nodes connected through links.

Advantage of Hierarchical Database Model are:

1. conceptual Simplicity

2. Database Security

3. Data Independence

4. Data integrity

Disadvantage of Hierarchical Database Model are:

1.Complex implementation

2. Difficult to manage

3. Lacks structural independence

4. Lacks of standard

5....

Data integrity is the accuracy, completeness, and quality of data as it's maintained aver time and across formats. preserving the integrity of your company data is a constant process.

The importance of data integrity in protecting yourself from the data loss or a data leak cannot to be overstated: in order to keep your data safe from outside forces with malicious intent, you must first ensure that internal users are handling data correctly. By implementing the appropriate data validation and...

The benefits of Centralized Database are:

• It is simple to implement and manage.
• It has less or no risk of data loss.
• It has a low cost of implementation and operation.
• It is suitable for a small organization with limited data and users.
• High Security can be provided.

it is a data object used for documenting complex software system designs in a systematic diagram which makes them easy to understand.

Data modelling techniques:

Hierarchical Technique:

it is a treelike structure, which has a root node, and the other nodes originate from the initial root node, which is sorted in a particular order. this type of model is rarely used nowadays.

Object-oriented Model:

This approach creates objects with related data and allows advanced techniques like data abstraction,...

The purpose of E-R diagram are the database analyst/designer gains a better understanding of the information to be contained in the database through the process of constructing the E-R Diagram. The E-R Diagram serves as a documentation tool. Finally, The E-R Diagram is used to communicate the logical Structure of the database to users. In particular the logic of the database to users.

The different used in E-R diagram with their meaning are:

1.Rectangl:It represent the entity. It contains...

The advantages of using a database rather than several separate files are:

Data redundancy: A database can store different types of data in different tables which can be related to one another, but these data will be stored multiple times if we plan to store these in different files. A database solves this by normalizing the data.

Easy access: A user can complex query data from a database. Separate files cannot be queried and would need a different program to do it.

Major responsibilities of a...

A domain is the set of possible values for a given attribute, and it can be considered as a constrait on the value of the attribute, such as value of an attribute marks of a subject must be integer value like 56 and it should be withwin the range of 0 to full marks.

A tuple is a complete row of the table . It is also called a record . It is data sets representing attributes of a single item. A data model define how data are organized in database and how the data can be accessed. The...

Prototyping is a process of quickly putting together a working model in order to test various aspects of a design illustrate ideas or features and gather early user feedback.

The role of database Administrator is:

1. Defining the internal schema: The DBA must define how the data is to be represented in the stored database. This process is usually referred to as physical database design.

2.Defining the external Schema: The DBA must also decide exactly what information is to be stored inthe database. This process is usually called as a logical (sometimes conceptual) database design.

3. Liaising with users: It is the business of the DBA to liaise with user to ensure...

The four guiding principles used in Database design are :

• Usability
• Extensibility
• Data Integrity
• Performance

Data security can be applied using a range of techniques and technologies, including administrative controls, physical security, logical controls, organization standards, and other safeguarding techniques that limit access to unauthorized or malicious users or processes.

It can be implemented are:

1. Protect the IT Infrastructure
2. Performance Comprehensive and Regular Audits.
3. Limit Data Access.
4. Remove Stale Information and Put Secure Backup in Place.
5. Change Your Mindset.

Database Management Systems (DBMS) are software systems used to store, retrieve, and run queries on data. A DBMS serves as an interface between an end-user and a database, allowing users to create, read, update, and delete data in the database.

Advantages:

1. Sharing:

DBMS helps create a data environment where many users can come and

use properly managed data.

2. Security:

A database admin can allow read and write access to any users with the database which improves the security and avoids data...