DataBase

DataBase

1. 2.2

   • 2.2.1 Three-Schema Architecture
     • Internal level
       • Describes physical storage structure of the database
     • Conceptual level
       • Describes structure of the whole database for a community of users
     • External or view level
       • Describes part of the database that a particular user group is interested in
   • 2.2.2 Data Independence
     • Capacity to change the schema at one level of a database system Without having to change the schema at the next higher level Types: Logical, Physical