chapter 5 :Managing Knowledge and Data

Difficult to manage data for many reasons:

•       Amount of data increasing exponentially over time;

•       Data are scattered throughout organizations;

•       Data obtained from multiple internal and external sources;

•       Data degrade over time;

•       Data subject to data rot;

•       Data security, quality, and integrity are critical, yet easily jeopardized;

•       Information systems that do not communicate with each other can result in inconsistent data.

Data governance is an approach to managing information across an entire organization.

Master data management is a process that spans all of an organization’s business processes and applications.

Master data are a set of core data that span all of an enterprise’s information systems.

The Database Approach

 Database management system (DBMS) minimize the following problems:

Data redundancy: The same data are stored in many places.

Data isolation: Applications cannot access data associated with other applications.

Data inconsistency: Various copies of the data do not agree.

DBMSs maximize the following issues:

Data security: Keeping the organization’s data safe from theft, modification,

     and/or destruction.

Data integrity: Data must meet constraints (e.g., student grade point averages

     cannot be negative).

Data independence: Applications and data are independent of one another.

     applications and data are not linked to each other, meaning that

     applications are able to access the same data.

Data Hierarchy

A bit is a binary digit, or a “0” or a “1”.

A byte is eight bits and represents a single character (e.g., a letter, number or symbol).

A field is a group of logically related characters (e.g., a word, small group of words,

     or identification number).

A record is a group of logically related fields (e.g., student in a university database).

A file is a group of logically related records.

A database is a group of logically related files.

The data model
 is a diagram that represents the entities in the database and their relationships.

An entity is a person, place, thing, or event about which information is maintained.

     A record generally describes an entity.

An attribute is a particular characteristic or quality of a particular entity.

The primary key is a field that uniquely identifies a record.

Secondary keys are other field that have some identifying information but typically do not

     identify the file with complete accuracy

A database management system is a set of programs that provide users with tools to add, delete, access, and analyze data stored in one location.

The relational database model is based on the concept of two-dimensional tables.

Structured query language allows users to perform complicated searches by using

     relatively simple statements or keywords.

Query by example allows users to fill out a grid or template to construct a sample or

     description of the data he or she wants.

Normalization is a method for analyzing and reducing a relational database to its most streamlined form for minimum redundancy, maximum data integrity, and best processing performance.

A data warehouse is a repository of historical data organized by subject to support

     decision makers in the organization.

Historical data in data warehouses can be used for identifying trends, forecasting, and makin comparisons over time.

Knowledge management is a process that helps organizations manipulate important

knowledge that is part of the organization’s memory, usually in an unstructured format.

Knowledge that is contextual, relevant, and actionable.

Intellectual capital is another term often used for knowledge.

Explicit knowledge: objective, rational, technical knowledge that has been documented.

Tacit knowledge: cumulative store of subjective or experiential learning.

     Examples: experiences, insights, expertise, know-how, trade secrets, understanding,skill sets, and learning