Data and Information Management

Data

• Data is raw or isolated facts used to produce information.
• Data can be organized in three layers: operational, reconciled, and derived.
• Operational data is stored in various operating systems within and outside the organization.
• Reconciled data is stored in data warehouses and operational data stores, and is detailed and current.
• Derived data is stored in data marts and is selected, formatted, and aggregated for decision support applications.

Information

• Information is processed, organized, or summarized data.
• Information communicates meaningful messages to recipients for decision-making.
• Data is processed to create information.
• Information reduces uncertainty, reveals alternatives, and influences action.

Data Warehouse

• A data warehouse is a collection of data designed to support management decision-making.
• It is subject-oriented, integrated, time-variant, and non-updatable.
• It supports business intelligence and contains a wide variety of data.
• It focuses on business intelligence, external data, and time-variant data.
• Data warehousing is the process of extracting meaning and information from data assets using data warehouses.

Data Dictionary

• A data dictionary is a mini database management system that manages metadata.
• It documents data elements of a database.
• It is an integral part of the Database Management System (DBMS).
• It stores metadata and information about the database, attribute names, and definitions for each table.
• It stores information about the database schema, physical database design, users, responsibilities, access rights, transactions, applications, relationships, and data items referenced by transactions.

Records

• A record is a collection of logically related fields or data items.
• Each field has a fixed number of bytes and a fixed data type.
• Records are retrieved or updated using programs.

Files

• A file is a collection of related records.
• Records in a file can be of the same type (fixed-length records).
• Records in a file can have different sizes (variable-length records).

Database

• A database is a collection of logically related data stored together to meet the information needs of an organization.
• It is designed to eliminate harmful or unnecessary redundancy.
• It serves multiple applications and is managed by a DBMS.