Database Definition

is a collection of related files containing records on people, places, or things.

Each of these generalized categories representing a person, place, or thing on which we store and maintain information is called an

Each entity has specific characteristics

A type of logical database model that treats data as if they were stored in two- dimensional tables called relations. It can relate data stored in one table to data in another as long as the two tables share a common data element.The most common type.

A grouping of characters into a word, a group of words, or a complete number, such as a person's name or age.

Are commonly referred to as records, or, in very technical terms, as tuples.

A field in a record that uniquely identifies instances of that record so that it can be retrieved, updated, or sorted.

------ Unique identifier for all the information in any row of a database table.

------ Field in a database table that enables users to find related information in another database table.

------ A methodology for documenting databases illustrating the relationship between various entities in the database.The most important piece of information provided by an entity- relationship diagram is the manner in which two tables are related to each other. Tables in a relational database may have one- to- one, one- to- many, and many- to- many relationships.

------ The process of streamlining complex groups of data to minimize redundant data elements and awkward many- to- many relationships, and increase stability and flexibility.

------ Rules to ensure that relationships between coupled database tables remain consistent.

DBMS that support a relational database.In a relational database, three basic operations, as shown in Figure 5- 8, are used to develop useful sets of data: ------ select, project, and join.