Databases and Information Management Short Questions

Define the term data.

A collection of raw facts and figures is called data. Data is collected from different sources. Data may consist of numbers, characters, symbols or pictures, etc.

Define the term information.

The processed data is called information. Information is an organized and processed form of data. It is more meaningful than data and is used for making decisions. Data is used as input for the processing and information is the output of this processing.

What is the difference between data and information?

Data is a set of raw facts and information is processed form of data. Data is input and information is the output of the computer. Data is difficult to reproduce but the information is easier to reproduce. Data is not used in decision-making but the information is used in making decisions.

What is metadata?

Metadata can be defined as data about ‘data. It is used to describe the properties and characteristics of some other data. Metadata describes the size, format, and other characteristics of data. It also includes the rules and constraints about data.

What is a database?

The database can be defined as an organized collection of related data. The word “organized” means that data is stored in such a way that the user can store, manipulate and retrieve data easily. The word “related” means that a database is normally created to store the data about a particular topic.

What is the table? Why is it used?

The table is the fundamental object of the database structure. The basic purpose of a table is to store data. A table consists of rows and columns. A table is a very convenient way to store data. You can easily manipulate the data in a table.

What is the row?

Rows are the horizontal part of the table. It is a collection of related fields. For example, in the above table, we have three rows. Each row contains a record of a different person.

What are columns?

Columns are the vertical part of the table. For example, in the above table, all values under The “Name” field makes a column.

What is a field?

A field is a combination of one or more characters. It is the smallest unit of data that can be accessed by the user. A field is identified uniquely by field name.

What is a file?

A file or data file is a collection of related records. Files are stored in disk-like hard disk, CD-ROM or DVD-ROM, etc.

Define database management system.

A database is a group of related data files. For example, a student database may have data files like Students file, Fee file, Attendance file, and Exam file, etc. The data in the data files can be accessed by using a database management system.

What is the purpose of using the primary key?

A primary key is a field or group of fields that are used to identify each record uniquely in a file. It is also known as a key field. The data in the key fields are unique for each record. For example, the Student ID field identifies each student uniquely because no two students can have the same ID.

What is the purpose of using foreign keys?

A foreign key is a field or combination of fields in a table that reference a primary key in another relation. The key connects to another table when a relationship is being established between two tables. A table may contain many foreign keys.

List different types of relationships.

Different types of relationships are as follows:

One-to-One Relationship — This type of relationship is used when “for each record in the first table, there is only one record in the second table and for each record in the second table, there is only one record in the
first table”.

One-to-Many Relationship — This type of relationship is used when “for each record in the first table, there are one or more records in the second table and for each record in the second table, there is only one record
in the first table”.

Many-to-Many Relationship — This. type of relationship is used when “for each record in the first table, there are one or more records in the second table and for each record in the second table, there are one or
more records in the first table”.

What do you know about referential integrity?

Referential integrity is a rule that preserves the defined relationship between the tables when records are added or deleted. Referential integrity means that you cannot enter a value in a foreign ad in a field that does not have a corresponding value in the primary key field of the related table.

Why is referential integrity used?

Referential integrity is applied when the data of an entity is stored in more than one table. When two tables are linked through a relationship, one table is called the master table and the other is called the child table.

List some advantages of using referential integrity.

The most important advantages of using referential integrity are as follows:
1. If the record does not exist in the master table, it cannot be stored in the child table.
2. A record cannot be deleted from the master table if a related record exists in the child table.

What is data validation?

The process of comparing data to a set of rules or values to find out if the data is correct is called data validation. Many programs perform validity checks to ensure the correctness of data. The validity checks are also called validity rules.

List some important types of validity ie:

Alphabetic/Numeric Check - Alphabetic check ensures that the user enters only alphabetic data in a field. A numeric check ensures that the user enters only numeric data in a field.

Range Check — It determines whether the entered number is within the specified range.

Consistency Check — It tests the data to ensure that it is logical.

Completeness Check ensures that data in a field exists. It stops the user from leaving a field blank.

What is a file processing system?

In a typical file processing system, each department in an organization has its own set of files. The files are designed especially for their own applications. The records in one file are not related to the records in any other file.

List different types of file organization.

Sequential File Organization - In sequential file organization, records are stored one after the other. The records are normally stored in ascending or descending order. This order is based on key.

Indexed File Organization - In indexed file organization, records are stored in ascending or descending
order. The order is based on a value called key as in sequential file organization. Additionally, an indexed
file organization maintains an index in a file.

Direct File Organization - Indirect file organization, the key value of a record is used to determine the
location to store the record.

What do mean by sequential access?

The records in sequential file organization are retrieved sequentially. This type of retrieval is known as sequential access. It means that records are accessed one after the other in the same sequence in which they are stored in the file.

What is the major disadvantage of sequential access?

The major disadvantage of sequential access is that it is very slow. If the the-last record is to be retrieved, all preceding records are read before reaching the last record.

What is hashing technique?

The implementation of direct file organization becomes complex in some situations. It becomes difficult to specify the relative location to store records. A mathematical formula can be used to find the relative location. This method is known as hashing.

What is an index?

An index consists of key values and the corresponding disk address for each record in the file. Index refers to the place on a disk where a record is stored. The index file is updated whenever a record is added or deleted from the file. When the file is processed, the index is retrieved from the disk and copied to the main memory.

What is random access?

Direct or random access means that any record can be accessed directly without reading the preceding records. When a record is to be retrieved, its key value is retrieved from the index file. The index also contains the corresponding address of the disk where the record is stored. This address is then used to access the record on the disk. Direct or random access is faster than sequential access.

What do you know about data redundancy?

Data redundancy means that data in a database appears only once and is not duplicated. For example, the data of a student in the college database is stored in one table. We can access this table for different purposes.

What are consistency constraints?

Consistency constraints are the rules that must be followed to enter data into the database. If data does not fulfill these constraints, it cannot be entered into the database. Database management systems provide an easy way for applying different consistency constraints that ensure the consistency of the data in databases.

What is data atomicity?

A collection of all steps required to complete a process is known as a transaction: The atomicity means that either one transition should take place as a whole or it should not take place at all. This property ensures that the database will always have correct and consistent data.

What is meant by data security?

Data security is the protection of the database from unauthorized access. The database management system provides several procedures to maintain data security. The security is maintained by allowing access to the database through the use of passwords. Not every use of a database system should be able to access all the data.

Application development takes less time with DBMS than with the file system. Why?

A database organizes data more efficiently than a file processing system. It is often easier and faster to develop programs that use this data. Many database management systems also provide several tools to assist in program development. So it reduces the overall time for developing applications.

What do you mean by the compactness of data?

The database management system stores data with compactness and efficiency. It requires less storage space than the file system. It saves storage resources of the system and memory is not wasted.

How data can be shared using DBMS?

Once a database is developed, it can be used by, several users in the organization. The database can also be shared by different applications. If a new application requires the same data, it can share the existing database instead of developing it again.

What is data independence?

The database approach provides the facility of data independence. It means that the data and the application programs are separate from each other. You can change data storage structures and operations without changing the application programs.

List some disadvantages of the database approach.

1. High Cost of DBMS — DBMS is expensive to purchase database management software.

2. Higher Hardware Cost - DBMS may require additional memory and processing power:

3. Higher Programming Cost - The programmers need a thorough knowledge of the system to use it.

4. More Chance of Failure - In DBMS, all resources and components are centralized. If any of these components fail, the whole system stops.

5. Complexity & Performance - In some applications, DBMS may run less efficiently as compared to file
processing systems.

What is a database management system?

A database management system is a collection of programs that are used to create and maintain a database. DBMS is a general-purpose software system. It provides the facility to define the structure of the database. It provides the facility to store the data on some storage medium that is controlled by the DBMS. It provides the facilities to insert, delete, update and retrieve specific data.

What is the use of a data dictionary?

The data dictionary contains data about each file in the database and each field in these files. For each file, it stores the details such as file name, description, file’s relationship to other files, and the number of records in the file. For each field, it stores details such as field name, description, field type, field size, default value, validation rules, and field’s relationship to other fields.

What is a relational database?

Ina relational model, data is stored in relations. The relation is another term used for the table. A table in a database has a unique name that identifies its contents. Each table can be called an intersection of rows and columns.

Define the terms relation, tuple, attribute, domain, degree, and cardinality.

Relation: Ina relational model, data is stored in relations. The relation is another term used for the table.
Tuple: Every relation or table consists of many tuples. Tuples are also ‘called records or rows.
Attributes: An attribute is a named column of a relation. Attributes are also called characteristics.
Domain: A domain is a collection of all possible values of one or more attributes.

Degree: The number of attributes is called the degree of that relation.
Cardinality: The number of rows is called the degree of that relation.

What is structured query language?

Structured Query Language is a data sublanguage. It means that it only has language statements for database definition and processing. SQL was ‘developed by IBM and is endorsed as a national standard by the American National Standard’ Institute (ANSI).

What is an object-oriented database?

Object-oriented database stores data in objects. An object is an item that can contain the data and functions to process that data. For example, an ‘object Student may contain. data about the student such as StudentID, Name, and Marks, etc. It may also contain functions to process this data such as printing the record of students, calculating the average marks of the students, etc.

What is a multimedia database?

A Multimedia database is used to store images, audio clips, and video clips. For example, a geographic information system database can store maps in a multimedia database. A television news station database can store audio and video clips etc.

What is a groupware database?

Groupware database is used to store documents such as schedules, calendars, manuals, memos, and reports, etc.

What is a computer-aided design database?

A computer-aided design database is, used to store data about engineering, architecture, and scientific designs. It may include a list of components of the item being designed, the relationship among the components, and previous versions of the designs.

What is a hypertext database?

A hypertext database is used to store text links to other types of documents. A hypermedia database contains text, graphics, video, and sound. The Web contains a variety of hypertext and hypermedia databases.

What is Web database?

A web database is used to link to n e-form on a Web page. The web browser sends and receives data between the form and the database.

What is object query language?

Object-oriented and object-relational databases use a query language known as an object query language to manipulate data. QOL is similar to SQL. It uses the almost same rules and keywords as SQL. Not all object databases support this language yet.

What is a centralized database system?

A type of database system in which all system components reside at a single computer or site is known as a centralized database system. The system components include the database and the DBMS etc. The users access the centralized database system témotely via terminals connected to the site.

What is a decentralized database?

A type of database system in which the database is stored on computers or sites at different locations is known as a decentralized database system. In a decentralized database, the computers are not interconnected via a network. So the users at various sites cannot share data. It is a collection of independent databases.

What is distributed database system?

A type of database system in which the database is stored physically across computers or sites at different locations is known as a distributed database system. The computers in a distributed database system are connected together by a data communication network.

What are multi-dimensional databases?

A database that stores data in dimensions is, called a multi-dimensional database. Relational database stores data in two dimensions but MDDB can store more than two dimensions of data. These multiple dimensions are also known as hypercubes and are used to access and analyze any view of data.

List some roles of database analysts & administrators.

Data administrators are the users who are responsible to maintain the whole database system. Different responsibilities of a database administrator include installation of software, monitoring of database system, solution of problems, assigning permission to different users, taking regular backups of the database, and restoring the system in case of any problem.

Define the role of a data administrator.

The data administrator is responsible for the whole information resource. He develops the requirements for database develops logical design and other non-technical functions. He also controls and manages the database, establishes data standards, communicates with users, Prepares logical design, develops data dictionaries, plans the development of database and application programs, trains users, and maintains documentation.

List some qualities of valuable information.

Accurate: Accurate information is correct information. Incorrect information leads to the wrong decisions.
Verifiable: It means that the user can prove the information is correct or incorrect.
Timely: Information is meaningful within the specified time period and becomes useless as time passes.
Organized: It means that the information should be arranged to particular requirements.
Useful: It means that the information is meaningful to the person who receives it.
Accessible: It means that the information should be available when it is needed.
Cost-Effective: It means that information should cost less than the value of the resulting information.

How can information be used by managers?

Planning: It includes the establishment of goals and objectives. It also includes the decisions about the strategies required to achieve these goals and objectives.
Organizing: It includes identifying and combining the resources to reach the goals and objectives. It also includes setting up the management structure of the organization such as departments.
Leading: It involves instructing and authorizing others to perform the necessary work.
Controlling: It involves measuring performance and taking corrective decisions if required.

List different levels of users and their responsibilities.

Executive Management: It includes the highest management positions in the organization. This management determines the long-range direction of the organization and is responsible for strategic decisions such as the overall goals and objectives of an organization.

Middle Management: It implements the strategic decision of executive management. These managers make tactical decisions.

Operational Management: It supervises the production, clerical, and other non-management employees of the organization. It makes operational decisions and monitors day-to-day activities.
Non-Management Employees: Non-management employees are production, clerical and staff
personnel. These employees also need the information to perform their jobs.

Define information systems.

A set of components that work together to produce information is called an information system. An information system consists of hardware, software, data, people, and procedures.

List different types of information systems.

Office information system: It is used to increase the productivity of employees. It helps the employees to perform different tasks using computers and other electronic devices.

Transaction Processing Systems: It is used to store and process day-to-day business activities. This system processes data faster reduces clerical costs and improves customer service. Management information system: It is used to generate timely, accurate, and organized information for the managers and other users.

Decision support system: It is used to analyze data ad make decisions. Different managers require different types of information. DSS provides information for different types of users according to their needs.

Data warehouse: It is a large database system. It stores and manages the data required to analyze historical and current transactions. It is used to access the transactions and their summary quickly.

Expert System: A system that stores the knowledge of human experts and imitates human reasoning for making decisions is called an expert system. It is the combined subject knowledge and experience of human experts.

Define OLAP, MOLAP and ROLAP.

The programs that analyze data are known as online analytical processing (OLAP) applications. OLAP applications that use multidimensional databases are called MOLAP. The OLAP applications that use relational databases are called ROLAP.

What is an executive information system?

An executive information system is a special type of DSS. It supports the strategic information needs of executive management. It presents information as charts and tables that show trends, rations, and statistics, etc.

Define web farming.

Data warehouse usually consists of one or more databases and many sources of data. These sources include internal and external sources. Some data warehouses also use web farming for external data. Data farming is a process of collecting data from the Internet for the data warehouses.

What do you mean by clickstream?

Clickstream is a collection of actions taken by the users through a website. The organization can assess the preferences of the users with the help of a clickstream.

What is the use of artificial intelligence?

Artificial Intelligence is the application of human intelligence to computers. This technology takes appropriate actions to complete a job. These actions are based on logical assumptions and prior experience. It is used in speech recognition, logical reasoning, and creative responses.

List different types of information Benereted by MIS.

MIS creates three types of information:

Detailed Report - It contains only transactions.

Summary Report - It consolidates data to review it quickly and easily. It normally contains totals, tables, and graphs.

Exception Report - It identifies data outside of a normal condition. This condition is called exception
criteria. It defines normal activity or status range.

Why do people use databases for information-handling tasks?

1. Databases make it easier to store large quantities of information.

2. Databases make it easier to retrieve information quickly and flexibly.

3. Databases make it easy to organize and reorganize information.

4. Databases make it easy to print and distribute information in many ways.

List and describe each of the components in the data hierarchy.

The data hierarchy includes bits, bytes, fields, records, files, and databases. Data are organized in a hierarchy that starts with the bit. It is represented by 0 or 1. Bits can be grouped to form a byte to represent one character, number, or symbol. Bytes can be grouped to form a field such as a name or a date. The related fields can be grouped to form a record. Related records can be collected to form files and related files can be organized into a database.

Write two important characteristics of a relational database.

Two important characteristics of relational databases are as follows:
1. All data in a relational database is stored in tables.
2. All data from a relational database is retrieved as tables.

What is a query?

A database object that is used to retrieve data is called a query. The query is written in database access language. It retrieves data from the database and displays it in the form of a table.

What is a form?

A graphical interface used to interact with the database is called form. It consists of text boxes, labels, and buttons that are used by the users for entering data easily.

What is an entity?

An entity is a person, place, thing, or event in real-world for which data is collected and maintained:

List out some uses of form.

The form is used to manipulate databases easily. It can be used to add data to the database, modify its data in the database, delete data from the database, retrieve and view. data from the database and search the required data from the database.

What is the main difference between form and report?

The main difference between form and report is that form is used to input data in the database. Then report is used to display data from tables.

What is a key field and how does it work in a relational database?

In relational databases, a key field is used to relate data in several files. Each record in the file has the same key field. It enables the field to be used to identify a record. The computer uses this key field at an index to locate records without having to read all the records in the files.

What are the three characteristics of a computerized information system (CIS)?

1. It provides essential services to organizations. It processes transactions and keeps exact records.
2. It collects critical data, processes it, stores it. It provides information throughout the organization.
3. It includes data, hardware, software, trained personnel, and procedures.

Differentiate bétween distributed database and decentralized database:

Both distributed and decentralized databases are stored on computers at multiple locations. In a decentralized database, a network does not interconnect the computers. The users at various sites cannot share data. It is a collection of independent databases. In distributed databases, data is stored across multiple distant sites. The computers are connected together by a data communication network.

Why are relational databases more popular than object databases?

Relational databases are more common and can store far more data in relational format. The users are more familiar and comfortable with relational databases. Organizations are reluctant to make the conversion to OOP because it is very expensive. Its expenses are more than its advantage cannot share data. It is a collection of independent databases. In distributed databases, data is stored across multiple distant sites. The computers are connected together by a data communication network.

Why are relational databases more popular than object databases?

Relational databases are more common and can store far more data in relational format. The users are more familiar and comfortable with relational databases. Organizations are reluctant to make the conversion to OOP because it is very expensive. Its expenses are more than its advantage.

Define rollback and rollforward.

In a rollback, we undo changes made by partially processed transactions. We apply before images to the changed database data. The valid transactions that were in process at the time of the failure are restarted. In a roll forward, the database is restored using the saved data. All valid transactions since the save are reapplied. We apply after images to the restored database data.

List and describe some of the problems of the traditional file environment.

Data redundancy is the presence of duplicate data in multiple data files. In this situation, confusion results because the data can have different meanings in different files.

Program-data dependence is the tight relationship between data stored in files and the specific programs required to update and maintain those files. This dependency is very inefficient, resulting in the need to make changes in many programs when a common piece of data, such as the zip code size, changes:

Lack of flexibility refers to the fact that it is very difficult to create new reports from data when needed.
Poor security results from the lack of control over the data because the data are so widespread.

Data sharing is virtually impossible because it is distributed in so many different files around the organization.

Differentiate between file processing system approach and database approach.

File processing system creates the problems of data duplication and isolated data. In the database approach, many programs and users share data. It minimizes data redundancy, improves data integrity, permits easier access, and reduces development time. But database approach can be complex and may require more memory and. processing power.

In a rollback, we undo changes made by partially processed transactions. We apply before
images to the changed database data. The valid transactions that were in process at the time of the
failure are restarted.

Ina roll forward, the database is restored using the saved data. All valid transactions since the
save are reapplied. We apply after images to the restored database data.

List and describe some of the problems of the traditional file environment.

Data redundancy is the presence of duplicate data in multiple data files. In this situation, confusion results because the data can have different meanings in different files.

Program-data dependence is the tight relationship between data stored in files and the specific
programs required to update and maintain those files. This dependency is very inefficient, resulting in
the need to make changes in many programs when a common piece of data, such as the zip code size,
changes:

Lack of flexibility refers to the fact that it is very difficult to create new reports from data when needed.
Poor security results from the lack of control over the data because the data are so widespread.

Data sharing is virtually impossible because it is distributed in so many different files around the organization.

Differentiate between file processing system approach and database approach.

File processing system creates the problems of data duplication and isolated data. In the database approach, many programs and users share data. It minimizes data redundancy, improves data integrity, permits easier access, and reduces development time. But database approach can be complex and may require more memory and. processing power.

 

 

• Databases and Information Management