EXAM 2

• an organized collection of structured information, or data, typicallystored electronically in a computer system

  Database
• the physical location of the data. It can be a hard drive,optical disk, or flash drive

  Physical Database
• It is how the user sees the data on the computer monitor

  Logical View
• It refers to how data are physically stored in the Database

  Physical View
• Unlike the flat-file approach, all data are combined into a single largestorage. The storage can be access by various application programs

  Data Integration
• Data can be easily shared in a database model. It became possible dueto the integration of data. Databases are easily browsed to research a problem or obtain detailed information underlying a report

  Data Sharing
• Because data and the programs that use them are independentof each other, each can be changed without changing the other. This facilitates programming and simplifies data management.

  Data independence
• In a database system, relationships, such as theassociation between selling costs and promotional campaigns, can be explicitly defined and used in the preparation of management reports.

  Cross-functional analysis
• An efficient information system captures and stores data only once. These data must be stored in central storage and must be available to all users who need it. However, this structure is not possible in a flat-file environment.

  Data Storage
• When data is stored in multiple storage, a problem will arise if one user updates the data. For example, the user 1 in figure 1 updates the data B, user 2 and 3 should also update the same data in their own files. These multiple updates are an additional cost of data management

  Data Updating
• Multiple storages also create another problem when one user failed to update the data

  Currency of information
• is a collection of names, definitions, and attributes about data elementsthat the Database used or captured

  Data Dictionary
• is a programming language within the DBMS thatbuilds the data dictionary, creates the Database, describes logical views for each user. It specifies record or field control. It merely describes the physical Database of the DBMS

  Data definition language (DDL)
• is a programming language that manipulates database content, including the data elements (name, price, etc.)creation, updates, insertions, and deletions. In other words, DML is the one responsible for the daily operation of the Database

  The data manipulation language (DML)
• is a high-level language that contains powerful, easy-to-use commands that enable users to retrieve, sort, order, and display data. Report writers use DQL to generate reports like financial statements or top customers

  The data query language (DQL)
• An abstract representation of database contents.

  Data Model