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IST 195 (15)
Rubin (11)
Chapter 11

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Department
Information Studies
Course
IST 195
Professor
Rubin
Semester
Fall

Description
Chapter 11 • Database: collection of data organized in a manner that allows access, retrieval, and use of that data • Database management system: users create a computerized database; sort and retrieve data from the database; and create forms and reports from the data in the database. • Data integrity: quality of the data • Garbage in, garbage out (GIGO): points out the accuracy of output depends on the accuracy of input • Accurate information: error free • Verifiable information: proven as correct/incorrect • Timely information: age suited to its use • Organized information: arranged to suit the needs +requirements of the decision maker • Accessible information: available when the decision maker needs it • Useful information: has meaning to the person who receives it • Cost effective information: should provide more value than its costs to produce • Character: number, letter, space, punctuation mark, or other symbol • Field: combination of 1+ related characters or bytes and is the smallest unit of data a user accesses. • Field name: uniquely identifies each field. • Data type: specifies the kind of data a field can contain and how the field is used. • Record: group of related fields • Primary key: field that uniquely identifies each record in a file. • Composite key: primary key consists of multiple fields • Data file: file, collection of related records stored on a storage medium such as a hard drive or optical disc. • File maintenance: refers to the procedure that keep data current. • Validation: process of comparing data with a set of rules/values to determine if the data is correct. • Alphabetic check: ensures that users enter only alphabetic data into a field • Numeric check: ensures that users enter only numeric data into a field • Range check: determines whether a number is within a specified range • Consistency check: tests the data in 2+ associated fields to ensure that the relationship is logical +their data is in the correct format • Completeness check: verifies that a required field contains data • Check digit: number or character that is appended to or inserted in a primary key value • File processing system: each department or area within an organization has its own set of files. • Data dictionary: repository, contains data about each file in database and each field in those files. • Default value: value that the DBMS initially displays in a field. • Query: request for specific data from the database • Query language: consists of simple, English like statements that allow users to specify the data they want to display, print, store, update, or delete • Query by example: feature that has a graphical user interface to assist users with retrieving data. • Form: data entry form, window on the screen that provides areas for entering or modifying data in a database • Report writer: report generator, allows users to design a report on the screen, retrieve data into the report design, and then display or print the report • Principle of least privilege policy: users’ access privileges are limited to the lowest level necessary to perform required tasks • Backup: copy of the entire database should be made on a regular basis • Log: listing of activities that modify the contents of the database • Recovery utility: uses logs/backups and either a roll-forward or rollback technique to restore a database when it becomes damage/destroyed. • Rollforward: forward recovery, the DBMS uses the log to reenter changes made to the database since the last save or backup. • Rollback: backward recovery, DBMS uses the log to undo any changes made to the database during a certain period • Continuous backup: backup plan in which changes are backed up as they’re made • Data model: defines how users view the organization of the data • Relational database: database that stores data in tables that consist of rows +columns. • Table: file • Row: record • Column: field • Relationship: link within the data • Object oriented database: stores data in objects • Object: item that c
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