This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: stored. The data record consists of data fields and some implementation data. The end user is not generally concerned with these pointers and flags. The advantage of the three-level concept is Level 2 absorbs changes made at Level 3, such as using a new physical storage method, so that individual application programs in Level 1 do not need to be changes when the physical layer changes. In addition, data only needs to be stored in Level 2 once, and different programs can retrieve that data. 3) The four database models are: Hierarchical Model, parent child model; Network Model, more than one parent; Relational Model, items are related based on values stores; Object Model, stored and manages objects. Each consists of data, methods, attributes, and relationships between these objects and others....
View Full Document
This homework help was uploaded on 04/18/2008 for the course MIS 470 taught by Professor Mullen during the Spring '07 term at S. Connecticut.
- Spring '07