ITM 102 Lecture Notes - Lecture 7: Unique Key, Foreign Key, Database Model
9 Mar 2017
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Document Summary
Information data converted into a meaningful and useful context. Information granularity extent of detail within the information: data raw facts that describe the characteristics of an event, real-time information immediate, up-to-date information, real-time system provides real-tome information in response to requests. Characteristics of high quality information: accuracy, completeness, consistency, uniqueness, timeline. Sources of low-quality information: customers intentionally enter inaccurate information to protect privacy, different entry standards and formats, operators enter abbreviated or erroneous information by accident or to save time, external information contains inconsistencies, inaccuracies, and errors. Benefits of good information: high-quality information, good decisions. Transactional data: stored in databases, scm and crm maintain and access the data, most common is relational database management systems (dbms) Relating data through keys: primary key a field (or group of fields) contain values that uniquely identify a given record in a table, foreign key a primary key of one table that appears a field in another table.
