Database systems and database management
Types of databases:
– Hierarchical
– Mesh
– Object-oriented
– Relational
DBMS / Database Management System
A suite of programs used to manage large sets of structured data with ad hoc query capabilities for many types of users.
Database: A collection of data stored in a meaningful way that enables multiple users and applications to access, view and modify data as needed.
Database terms/jargon
– Record: Collecion of related data items
– File: Collection of record of the same type
– Database: Cross-referenced collection of files
– DBMS: Manages and controls the database
– Base relation: A table stored in a database
– Tuple: A row in a database
– Attribute: A column in a database
– Primary key: Columns that make each row unique
– View: Virtual relation defined by the database to control subjects from viewing certain data
– Foreign key: Attribute of one table that is the primary key of another table
– Cell: Intersection of a row and column
– Schema: Holds data that describes a database
– Data dictionary: Central repository of data element and their relationships.
– Cardinality: The number of rows in the relation.
– Degree: The number of columns in the relation.
– Domain: Is a set of allowable values that an attribute can take.