Database Models

Database Models

1. Flat Model

   • consists of a single, two-dimensional array of data elements,where all members of a given column are assumed to be similar values, and all members of a row are assumed to be related to one another.

2. Hierarchical Model

   • data is organized into a tree-like structure, implying a single parent for each record. A sort field keeps sibling records in a particular order.

3. Network Model

   • The network model expands upon the hierarchical structure, allowing many-to-many relationships in a tree-like structure that allows multiple parents.

4. Inverted File Model

   • the contents of the data are used as keys in a lookup table, and the values in the table are pointers to the location of each instance of a given content item. This is also the logical structure of contemporary database indexes, which might only use the contents from a particular columns in the lookup table.

5. Relational Model

   • The basic data structure of the relational model is the table, where information about a particular entity (say, an employee) is represented in rows (also called tuples) and columns.

6. Dimensional Model

   • a specialized adaptation of the relational model used to represent data in data warehouses in a way that data can be easily summarized using online analytical processing, or OLAP queries. In the dimensional model, a database schema consists of a single large table of facts that are described using dimensions and measures.