Database Management System

Data Management

CJC ACE | IT201

Data Access

•Timely and useful information requires accurate data. Such data must be properly generated and stored in a format that is easy to access and process. And, like any basic resource, the data environment must be managed carefully.

•Data management is a discipline that focuses on the proper generation, storage, and retrieval of data.

•Given the crucial role that data play, it should not surprise you that data management is a core activity for any business, government agency, service organization, or charity.

Databasae

•Efficient data management typically requires the use of a computer database.

•A database is a shared, integrated computer structure that stores a collection of:

•End-user data—that is, raw facts of interest to the end user.

•Metadata, or data about data, through which the end-user data are integrated and managed.

Metadata

•The metadata describe the data characteristics and the set of relationships that links the data found within the database.

Metadata

•For example, the metadata component stores information such as the name of each data element, the type of values (numeric, dates, or text) stored on each data element, and whether the data element can be left empty. The metadata provide information that complements and expands the value and use of the data. In short, metadata present a more complete picture of the data in the database. Given the characteristics of metadata, you might hear a database described as a “collection of self-describing data.”

Database Management System (DBMS)

•A database management system (DBMS) is a collection of programs that manages the database structure and controls access to the data stored in the database.

•In a sense, a database resembles a very well-organized electronic filing cabinet in which powerful software (the DBMS) helps manage the cabinet’s contents.

Database Management System (DBMS)

•The DBMS serves as the intermediary between the user and the database. The database structure itself is stored as a collection of files, and the only way to access the data in those files is through the DBMS.

•The DBMS receives all application requests and translates them into the complex operations required to fulfill those requests. The DBMS hides much of the database’s internal complexity from the application programs and users.

Advantages

Having a DBMS between the end user’s applications and the database offers some important advantages. First, the DBMS enables the data in the database to be shared among multiple applications or users. Second, the DBMS integrates the many different users’ views of the data into a single all-encompassing data.

Improved Data Sharing

•The DBMS helps create an environment in which end users have better access to more and better-managed data. Such access makes it possible for end users to respond quickly to changes in their environment.

Improved Data Security

•The more users access the data, the greater the risks of data security breaches. Corporations invest considerable amounts of time, effort, and money to ensure that corporate data are used properly. A DBMS provides a framework for better enforcement of data privacy and security policies.

Better Data Integration

•Wider access to well-managed data promotes an integrated view of the organization’s operations and a clearer view of the big picture. It becomes much easier to see how actions in one segment of the company affect other segments.

Minimized Data Inconsistency

•Data inconsistency exists when different versions of the same data appear in different places. For example, data inconsistency exists when a company’s sales department stores a sales representative’s name as Bill Brown and the company’s personnel department stores that same person’s name as William G. Brown, or when the company’s regional sales office shows the price of a product as $45.95 and its national sales office shows the same product’s price as $43.95. The probability of data inconsistency is greatly reduced in a properly designed database.

Improved Data Sharing

•The DBMS helps create an environment in which end users have better access to more and better-managed data. Such access makes it possible for end users to respond quickly to changes in their environment.

Improved Data Access

•The DBMS makes it possible to produce quick answers to ad hoc queries. From a database perspective, a query is a specific request issued to the DBMS for data manipulation—for example, to read or update the data. Simply put, a query is a question, and an ad hoc query is a spur-of-the-moment question. The DBMS sends back an answer (called the query result set) to the application. For example, when dealing with large amounts of sales data, end users might want quick answers to questions (ad hoc queries).

Improved Decision Making

•Better-managed data and improved data access make it possible to generate better-quality information, on which better decisions are based. The quality of the information generated depends on the quality of the underlying data. Data quality is a comprehensive approach to promoting the accuracy, validity, and timeliness of the data. While the DBMS does not guarantee data quality, it provides a framework to facilitate data quality initiatives.

Increased End-User Productivity

•The availability of data, combined with the tools that transform data into usable information, empowers end users to make quick, informed decisions that can make the difference between success and failure in the global economy.

Multiple Choice

____________ is a discipline that focuses on the proper generation, storage, and retrieval of data.

• Data Access

• Data Entry

• Data Management

Multiple Choice

is a core activity for any business, government agency, service organization, or charity.

• Data Entry

• Data Management

• Data Retrieval

• Data Storage

Multiple Choice

a set of data that describes and gives information about other data.

• Data Warehouse

• Meta Data

• Data Information

Multiple Select

A DBMS can help in many ways such as: (Choose 2)

• Minimizing data redundancy

• Keeping record of data

• Duplicating data

• Data Redundancy

Multiple Choice

End users have direct (unrestricted) access to the Database

• True

• False