Different types of Data Models

A data model in software engineering is an abstract model that documents and organizes the business data for communication between team members and is used as a plan for developing applications, specifically how data are stored and accessed. The main data models are Relational model, Network model,Hierarchicalmodel,Object-relational model, object relational functional data models

In the relational model of a database, all data is represented in terms of tuples, grouped into relations. A database organized in terms of the relational model is a relational database.

Diagram of database according to the Relational model. In the relational model, related records are linked together with a "key".The purpose of the relational model is to provide a declarative method for specifying data and queries: users directly state what information the database contains and what information they want from it, and let the database management system software take care of describing data structures for storing the data and retrieval procedures for answering queries.

The network model is a database model conceived as a flexible way of representing objects and their relationships. Its distinguishing feature is that the schema, viewed as a graph in which object types are nodes and relationship types are arcs, is not restricted to being a hierarchy or lattice.

A hierarchical database model is a data model in which the data is organized into a tree-like structure. The structure allows representing information using parent/child relationships: each parent can have many children, but each child has only one parent (also known as a 1-to-many relationship).

The model allows easy addition and deletion of new information. Data at the top of the Hierarchy is very fast to access. It was very easy to work with the model because it worked well with linear type data storage such as tapes. The model relates very well to natural hierarchies such as assembly plants and employee organization in corporations. It relates well to anything that works through a one to many relationship. For example; there is a president with many managers below them, and those managers have many employees below them, but each employee has only one manager.

 

 

25.What is a database? What are the advantages of using a database to organize data?

A database is a structured collection of data. The term database is correctly applied to the data and their supporting data structures. A general-purpose DBMS is typically a complex software system that meets many usage requirements to properly maintain its databases which are often large and complex.

Well known DBMSs include Oracle, IBM, Microsoft Access, Microsoft SQL Server, MySQL. A database is not different from DBMS, but DBMSs can inter-operate to some degree by using standards like SQL and ODBC together to support a single application built over more than one database. A DBMS also needs to provide effective run-time execution to properly support as many database end-users as needed.

The advantages of using a database are considerable. Without them, you would be hard-pressed to find a decent system of keeping and managing information. In recent years, the increased flexibility and user-friendliness of databases make these systems a crucial business component. Here are the top reasons for using a database:

Databases Save Time a database pulls up information with simple query. A user can enter in specific keywords in order to recall information. The database becomes a more efficient solution than paper files held in a file folder.

Databases Are More Secure
File cabinets can be compromised. They can be stolen, accidentally destroyed, or lost. Databases add another level of security to valuable information. Not only can a database be stored in a remote facility unaffected by devastating events such as fire or thievery, but a database can also be password protected. This locks out any eyes that should not view sensitive reports.

Databases Are Inexpensive Managers
Smaller businesses are always looking for ways to cut costs without cutting quality. A database can be a hefty investment initially, but, over the long term, it will save money by improving the efficiency of all employees, impressing customers who will not need to repeat their information and saving on paper costs.

 

 

	26.Database management component includes relational databases, basic SQL, data architecture issues. Relational Database is a collection of data items organized as a set of formally described tables from which data can be accessed easily. A relational database is created using the relational model. SQL (or Structured Query Language) is a special-purpose programming language designed for managing data in relational database management systems (RDBMS). SQL commands fall into one of 4 categories: SELECT - Retrieving data from one or more tables INSERT - Adding rows to a table UPDATE - Modifying existing rows in a table DELETE - Deleting one or more rows from a table Data architecture in Information Technology is consisting models, policies, rules or standards that govern which data is collected, and how it is stored, arranged, integrated, and put to use in data systems and in organizations. A database management system (DBMS) consists of several components: 1.Software is the set of programs used to process the database and to control and manage the overall computerized database 2.Hardware consists of a set of physical electronic devices such as computers, storage devices, I/O channels, electromechanical devices that make interface between computers and the real world systems etc. 3.Data is the most important component of the DBMS. The main purpose of DBMS is to process the data. 4. Procedures refer to the instructions and rules that help to design the database and to use the DBMS.
	27.Fundamental programming concepts including data types, control structures, modularization, and structure programming. Фундаментальные концепции программирования, включая типы данных, управляющие структуры, модульность, и структура программирования.     To construct any computer-based system, we must use some process to translate the idea for the use of the computer into lines of source code which can be compiled and executed. The programming language and the development tools used for constructing programs try to prevent the programmer making errors in the first place and, if errors are introduced, help finding and eradicating them quickly and efficiently C language provides various data types for holding different kinds of values. There are several integral data types, a character data type, floating point data types for holding real numbers and more. In addition you can define your own data types using aggregations of the native types. As you will see, the C standard usually does not specify exact sizes for the native types, preferring to set a basic minimum that all conforming implementations of C must meet. Implementations are free to go above these minimum requirements. This means that different implementations can have different sizes for the same type. The three fundamental control structures of structed programming language: 1-Sequence- it refers to the line-by-line execution.The program enters the sequence, does each step, and exits the sequence 2-Selection- it is the control structure which allows choice among different directions. Example,C++ provides different levels of selection - one-way selection(IF structure) - two-way selection (IF-ELSE structure) - multiple selection (SWITCH structure) 3- Iteration- it refers to looping. Example:C++ provides three loop structures: -WHILE loops -DO-WHILE loops -FOR loop
	28.Developing solutions for problems in interactive business applications. E-Business in Business: Businesses today are using Internet technologies to web-enable business processes and create innovative e-business.   THE FUNDAMENTAL ROLES OF IS APPLICATIONS IN BUSINESS Information systems perform three vital roles in any type of organization. That is, they support an organization’s: • Business processes and operations • Decision making by employees and managers • Strategies for competitive advantage   The Major Roles of IS: Examples Three major roles of the business applications of information systems include: • Support Business Processes – involves dealing with information systems that support the business processesand operations in a business. • Support Decision Making – help decision makers to make better decisions and attempt to gain a competitiveadvantage. • Support Competitive Advantage – help decision makers to gain a strategic advantage over competitors requiresinnovative use of information technology   e-BUSINESS IN BUSINESS The explosive growth of the Internet and related technologies and applications is revolutionizing the way businesses are operated and people work, and how information technology supports business operations and enduser work activities.Businesses are becoming e-business enterprises . The Internet and Internet-like networks – inside the enterprise( intranets ), and between an enterprise and its trading partners ( extranets ) – have become the primary informationtechnology infrastructure that supports the business operations of many companies. e-business enterprises rely onsuch technologies to: • Reengineer and revitalize internal business processes. • Implement electronic commerce systems among businesses and their customers and suppliers. • Promote enterprise collaboration among business teams and workgroups. e-business is defined as the use of Internet technologies to internetwork and empower business processes,electronic commerce, and enterprise communication and collaboration within a company and with its customers,suppliers, and other business stakeholders. Enterprise collaboration systems involve the use of groupware tools to support communication, coordination, andcollaboration among the members of networked teams and workgroups. An internetworked e-business enterprisedepends on intranets, the Internet, extranets, and other networks to implement such systems. Electroniccommerce is the buying and selling, and marketing and servicing of products, services, andinformation over a variety of computer networks. An internetworked e-business enterprise uses the Internet,intranets, extranets, and other networks to support every step of the commercial process
	29.Introduction to data and file structure. File-a data structure on secondary storage which acts as a non-volatile container for data. file structure-a pattern for arranging data in a file. data structure-a pattern for organizing data in a program. • Data and file structure Both involve: – Representation of Data – Operations for accessing data – Difference: – Data structures: deal with data in the main memory – File structures: deal with the data in the secondary storage Goal of the file structures: • What is performance – Time • Minimize the number of trips to the SS in order to get desired information • Group related information so that we are likely to get everything we need with fewer trip to the SS. – Memory • Balance the memory size and the time • How to improve performance – Use the right file structure • Understand the advantages disadvantages of alternative methods
	30.Extensive use of an event-driven programming language. In computer programming, event-driven programming (EDP) or event-based programming is a programming paradigm in which the flow of the program is determined by events—e.g., sensor outputs or user actions (mouse clicks, key presses) or messages from other programs or threads. Event-driven programming can also be defined as an application architecture technique in which the application has a main loop which is clearly divided down to two sections: · the first is event selection (or event detection) · the second is event handling. In embedded systems the same may be achieved using interrupts instead of a constantly running main loop; in that case the former portion of the architecture resides completely in computer hardware. Event-driven programs can be written in any language, although the task is easier in languages that provide high-level abstractions, such as closures. Some integrated development environments, such as Microsoft Visual Studio, provide code generation assistants that automate the most repetitive tasks required for event handling. There are four main typical uses and advantages of event driven programs, these are as follows – · Flexibility · Suitabilityforgraphicalinterfaces · Simplicityof Programming · Easeofdevelopment Flexibility Event driven programming is one of the most flexible programming language types. It allows the programmer to visually design the form to their needs and program the objects on the form with a huge range of sevents that can do different things when run. It gives the programmer more control over what they want the program to do when a user does something.   Suitability for graphical interfaces Because of the graphical way a programmer creates their program in an event driven programming language it is much suited to graphical user interfaces. When programming with an event driven language, the programmer can select different controls such as a command button and place it on the form where necessary. Then with very little code, the button can perform a process when the chosen event is noticed by the program. Event driven programming allows the user to use the program without following any certain routine, they have complete control over what actions they want the program to carry out.

 

31 database design, development, and administration.

Database design is the process of producing a detailed data model of a database. This logical data model contains all the needed logical and physical design choices and physical storage parameters needed to generate a design in a Data Definition Language, which can then be used to create a database. A fully attributed data model contains detailed attributes for each entity.

Database administration is the function of managing and maintaining database management systems (DBMS) software.

There are three types of DBAs:

1. Systems DBAs

2. Development DBAs.

3. Application DBAs

While individuals usually specialize in one type of database administration, in smaller organizations, it is not uncommon to find a single individual or group performing more than one type of database administration

Database development is a systematic process that moves from concept to design to implementation.

1. Define business processes: Many database development efforts begin by defining the key business and/or operational processes within the organization.

2. Determine scope of database development effort

3. Define the information needs.

4. Develop conceptual design

5. Develop logical data model

6. Develop physical design: With the logical data model in hand, developers move to the physical design, which involves determining the specific storage and access methods and structures.

7. Create and test database: Once this step is complete, developers can go ahead and create the database using whatever DBMS has been selected.

 

32Introduces data mining concepts and techniques, including associations rules, decision trees, cluster analysis, classification, logistic regression, text mining, and
web analytics

Data mining is a logical process that is used to search through large amount of data in order to find

useful data. The goal of this technique is to find patterns that were previously unknown. Once these

patterns are found they can further be used to make certain decisions for development of their businesses.

Association rule

Association and correlation is usually to find frequent item set findings among large data sets. Types of association rule:

1 Multilevel association rule

2 Multidimensional association rule

3 Quantitative association rule

Decision tree learning is a method commonly used in data mining. The goal is to create a model that predicts the value of a target variable based on several input variables.

Clustering

Clustering can be said as identification of similar classes of objects. By using clustering techniques we can

further identify dense and sparse regions in object space and can discover overall distribution pattern and

correlations among data attributes

. Classification

Types of classification models:

 Classification by decision tree induction

 Bayesian Classification

 Neural Networks

 Support Vector Machines (SVM)

 Classification Based on Associations

 

Logistic regression

In statistics, logistic regression is a type of regression analysis used for predicting the outcome of a categorical (a variable that can take on a limited number of categories) criterion variable based on one or more predictor variables.

Text mining

sometimes alternately referred to as text data mining, roughly equivalent to text analytics, refers to the process of deriving high-quality information from text. High-quality information is typically derived through the devising of patterns and trends through means such as statistical pattern learning.

Web analytics

is the measurement, collection, analysis and reporting of internet data for purposes of understanding and optimizing web usage.

 

 

33.Concentrates on the analysis phase of systems development.

Structured Analysis

Structured analysis is a traditional systems development technique that is time-tested and easy to understand. Because it describes the processes that transform data into useful information, structured analysis is called a process-centered technique. In addition to modeling the processes, structured analysis includes data organization and structure, relational database design, and user interface issues. Structured analysis uses a series of phases, called the systems development life cycle(SDLC) to plan, analyze, design, implement, and support an information system. Structured analysis relies on a set of process models that graphically describe a system. Process modeling identifies the data flowing into a process, the business rules that transform the data, and the resulting output data flow.

 

Object-Oriented Analysis

 

Whereas structured analysis regards processes and data as separate components, object-oriented analysis combines data and the processes that act on the data into things called objects. Object-oriented analysis defines the different types of objects that are doing the work and interacting with one another in the system and by showing user interactions, called use cases, are required to complete tasks.

O-O analysis uses object models to represent data, behavior, and by what means objects affect other objects, By describing the objects(data) and methods (processes) needed to support a business operation, a system developer can design reusable components that allow faster system implementation and decreased development cost. The object-oriented approach has many benefits, they provide naturalness and reuse.

 

 

34.Networks and distributed information-processing systems, office automation

A data processing facility may depart in varying degrees from the centralized data processing organization by implementing a distributed data processing (DDP) strategy. A distributed data processing facility is one in which computers, usually smaller computers, are dispersed throughout an organization. The objective of such dispersion is to process information in a way that is most effective based on operational, economic, and/ or geographic considerations, or all three. A DDP facility may include a central facility plus satellite facilities, or it may more nearly resemble a community of peer computing facilities. In either case, some form of interconnection is usually needed; that is, the various computers in the system must be connected to one another. As may be expected, given the characterization of centralized data processing provided here, a DDP facility involves the distribution of computers, processing, and data.

……..

An automated office information system (0 IS) attempts to perform the functions of the ordinary

office by means of a computer system. the OIS tasks include document preparation, document management,

communication, and aids in decision making. Such systems may be as

modest as a group of independent word processors, or as complex as a distributed set of large,

communicating computers. Within in this spectrum is a central computer with several interactive

terminals, or a set of small interconnected computers. In either system the office worker would

use a work station to perform his work, and that work station would be capable of electronically

communicating with other work stations.

An OIS is made up of a collection of highly interactive autonomous tasks that

execute in parallel;

 

35 Technical and organizational foundations of information systems
The technical basis of providing information technology tools are computers and office equipment facilities.
Funds of computer technology are the basis of all of the technical means of information technologies, and are designed primarily for the processing and transformation of various types of information used in management.
Equipment of communication technology provide one of the basic functions of management, the transfer of information within the system. Management and communication with the
external environment and make use of a variety of methods and technologies, including the use of computer technology
Means office equipment designed for mechanization of automation of management in all its forms.
A modern computer is a tool. Its principle of operation, electronic, and the appointment - automation of data operations. Flexible automation is based on the fact that the operation is performed with the data on pre-prepared and easily replaceable programs. Mainframe computers, based on the fact that all types of data submitted to it by means of a universal binary encoding
General control problems in organizations
Organizational effectiveness is maintained constant control, adaptation of its configuration and proportions to many changes in the external and internal (structure-forming) factors, which include:
· Prices and demand for goods and services, raw materials, labor costs and taxes;
· Bank interest rates;
· Administrative law;
· Production technology, including equipment;
· Number, qualifications, education, the ability of workers;
· Performance of personnel and equipment;
· Production areas, different standards and much, much more.
French engineer and researcher, the ideologue of the classical (administrative) school of Management, Henri Fayol proposed a system of 9 basic management principles that govern the regulatory and behavioral basis of the control system.
They’re:
1. division of labor
2. power and responsibility
3. discipline
4. undivided authority
5. unidirectionality of force (action)
6. combination of individual and common interests
7. remuneration staff of the Organization
availability of initiative harmony among the members of the organization

 

36 What is the difference between file-processing system and a database
system?

In file processing system a permanent system file is created for every new object. Application softwares are used to manipulate these files. SO characteristics (Some of them became its drawbacks) of file processing system are:-
1)Data redundancy and inconsistency
2)Difficulty in accessing data
3)Data isolation ie. data is in different formats and files.

In database system these issues where addressed, by data abstraction.
In DBMS, data is stored using 3 levels of abstraction
1)Physical Level: How data is stored
2)Conceptual level: What data is stored, relationship between data
3)View Level: What is visible to different users

· A database coordinates the physical and logical access to the data; a file-processing system only coordinates physical access to the data

· A DBMS reduces the amount of data duplication

· A DBMS is designed to allow flexibility in what queries give access to the data, where a file-processing system only allows pre-determined access to data (by specific compiled programs)

· A DBMS is designed to coordinate and permit multiple users to access data at the same time. A file processing system is much more restrictive in simultaneous data access