difference between relational table and flat field table

hi



can any one tell me teh diffrerence between flat field table and relational table and the advantage and disadvantage of these two type of table



any sources of inforamtion would be gratefu



l

hey man

hope this helps!!



Flat File Structure

A database with a single table is called a flat file structure. A flat-file structure is good only for extremely simple databases. A flat-file structure is not practical for most business applications. Many spreadsheets include some database features like sorting entries and counting or summarizing entries that meet certain criteria. Database features included in spreadsheets are based on a flat-file structure.



Hierarchical Data Model

The hierarchical data model is set up like a "forest" or collection of tree structures.



- a 搕ree?of records in which each record contains two elements

1. a root or master field, (a key), which identifies the type, location or ordering of the records;

2. subordinate fields which define the rest of the data within a record;

- all fields have only one 損arent? each parent may have many 揷hildren?

- advantage: speed and efficiency for certain kinds of applications. The hierarchical data model is a good choice when the data to be modeled is also like a tree.

- problem: how data is accessed is predefined; and each relationship must be explicitly defined when the database is created;



The hierarchical data model is a special case of the network data model. The best-known hierarchical database management system is IBM's IMS. It was originally a purely hierarchical system but has gained some nonhierarchical features as a result of practical needs. Figure C3 shows Accounts Receivable modeled using a hierarchical data model.