5 Computer -- DBMS Concept

What is the role of Database Administrator? What are the duties and responsibilities of a System Analyst?

1 Answers

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 that the data they requires is available, and to write the necessary external schemas.

4.Defining security and integrity rules: The DBA must be define security rules for the protection of data against unauthorized users. S/he must also define integeity rules for checking the accuracy or validity of data.

5. Defining backup and recovery procedures: The DBA must define backup and recovery procedures beacuse the damage to any portion of the system causes an error

The duties and responsibilities of a system Analyst are :

1. Defining requirement: It involves understanding user's requirements by interviewing user, finding out what information is being used in a current system, how it is used and what is their expectations towards the proposed system.

2. prioritizing requirement by consensus: Each user in the organization has some special information needs. It may not be possible to satisfy the needs of everyone due to the lack of computing capabilities, availability of programmers. Thus, there is a need to set priorities among the requirements of various users.

3.Gathering data, facts, and opinions of users: Having determined the information needs and their priority , the system analyst must be develop the system with the active and willing cooperation of all the users.

4.Analysis and evaluations: The system analyst analyses the working of the current information system in the organization. He then shifts throuhgh the facts and opinions gathered by him and find the best charateristics of a new or modified system.

5.Solving problems: A system analyst must suggest study the problem in-depth and suggest an alternative solution to the management. The relative difficulties in implementing each of the alternative and benefits of each must be considered so that a manager can pick what analyst considered as the best solutions.

6. Designing system: Once the specification is accepted, the system analyst designs the system. The design must be understandable to the system implemented and it must be modular to accomadate easily.

7. Evaluating system: A system analyst must evlauate a system after it has it user for a reasonable period of time The time at which evaluation is to be done, how is to be done, cooments of the users are to be gathered and used must be decided by the system analyst.

Define DBMS. List out objectives of DBMS.

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.

What is relational database model? Write its advantages.

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...

Differentiate between DBMS and RDBMS with example.

DBMS	RDBMS
1.A software that provides a systematic way of creating, retrieving and managing data in database	1.A DBMS that is based on the relational model introduced by E.F.Codd
2. Normalization is not present in DBMS	2. Normalization is present in RDBMS.
3.DBMS does not apply any security with regardsto data manipulation.	3.RDBMS define the integrity constraint for the purpose of ACID (Atomocity, comnsistency, Isolation and Durability) property.
4.Suitable to store a small amount...

Define DML and DDL with example.

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.

Differentiate between centralized and distributed database.

Centralized Database system	Distributed Database system
1. Data reside a single location	1. The data reside in serveral locations
2. Files are kept on the basis of the location of disk drives and names	2. Files are kept on the basis of names rather thanlocation.
3.It does not contain several or nodes.	3. It contains several computer(sites) and communicates with one to another through communication media.
4. No risk of data loss.	4. High risk of data theft, hacking ,etc.
5.Suitable...

Describe any two database model with diagram.

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...

What is MS Access? What are the uses of MS Access?

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

What is normalization? What are the advantages of normalization?

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. ...

What is Hierarchical Database Model? List out the advantages and disadvantages of Hierarchical Database Model.

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....

What do you understand by the term data integrity? Why it is important in designing a Database?

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...

Explain the benefits of Centralized Database.

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.

What is data mode? Explain about different modeling techniques.

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,...

What is the purpose of E-R diagram? List out the different symbols used in E-R diagram with their meanings and examples.

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...

Give two advantages of using a Database rather than a number of separate files. What are the major responsibilities of a Database Administrator?

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...

What are Domains and Tuples? What are the characteristics of good data model?

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...

What is prototyping?

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.

State the four guiding principles used in Database design.

The four guiding principles used in Database design are :

Usability
Extensibility
Data Integrity
Performance

What is data security? How it can be implemented?

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:

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

Difference between Database and DBMS with example.

Database	DBMS
A database is a collection of information in tables. Sometimes relations between them.	A database management system is a collection of programs that helps you to use the database.
The database itself cannot back itself up.	a DBMS backups the database ensuring the integrity of the data even after a system failure.
a database cannot handle multiple users at the same time.	A DBMS can handle and is designed for multiple queries at a time.
A very big amount of...

Define DBMS. Write its advantages and disadvantages.

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...

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