Database Structure

Hierarchical Database

A kind of database management system that linksrecords together like a family tree such that each record type hasonly one owner, e.g. an order is owned by only one customer.Hierarchical structures were widely used in the first mainframe database management systems. However, due to theirrestrictions, they often cannot be used to relate structures thatexist in the real world.

Network Database

The Network Database Model was created for three main purposes. These purposes include representing a complex data relationship more effectively, improving database performance, and imposing a database standard. The network model highly resembles the hierarchal model. Another characteristic is the network database model is composed of at least two record types including an owner, which is a record type equivalent to the parent type in the hierarchal database model, and the member record type which resembles the child type in the hierarchal model. The schema, subschema, and data management language are a few of the key components that make this database model unique. The schema used for this model is conceptual organization of the entire database as the database administrator intends.

Relational Database

A relational database is a collection of data items organized as a set of formally-describedtables from which data can be accessed or reassembled in many different ways without having to reorganize the database tables. The relational database was invented by E. F. Codd at IBM in 1970.

The standard user and application program interface to a relational database is the structured query language (SQL). SQL statements are used both for interactive queries for information from a relational database and for gathering data for reports.

In addition to being relatively easy to create and access, a relational database has the important advantage of being easy to extend. After the original database creation, a new data category can be added without requiring that all existing applications be modified.

A relational database is a set of tables containing data fitted into predefined categories. Each table (which is sometimes called a relation) contains one or more data categories in columns. Each row contains a unique instance of data for the categories defined by the columns. For example, a typical business order entry database would include a table that described a customer with columns for name, address, phone number, and so forth. Another table would describe an order: product, customer, date, sales price, and so forth. A user of the database could obtain a view of the database that fitted the user's needs. For example, a branch office manager might like a view or report on all customers that had bought products after a certain date. A financial services manager in the same company could, from the same tables, obtain a report on accounts that needed to be paid.

Object-Oriented Database

An object-oriented database management system (OODBMS), sometimes shortened toODBMS for object database management system), is a database management system (DBMS) that supports the modelling and creation of data as objects. This includes some kind of support for classes of objects and the inheritance of class properties and methods by subclasses and their objects. There is currently no widely agreed-upon standard for what constitutes an OODBMS, and OODBMS products are considered to be still in their infancy. In the meantime, the object-relational database management system (ORDBMS), the idea that object-oriented database concepts can be superimposed on relational databases, is more commonly encountered in available products.

Multi-dimensional Database
A multidimensional database (MDB) is a type of database that is optimized for data warehouse and online analytical processing (OLAP) applications. Multidimensional databases are frequently created using input from existing relational databases. Whereas a relational database is typically accessed using a Structured Query Language (SQL ) query, a multidimensional database allows a user to ask questions like "How many Aptivas have been sold in Nebraska so far this year?" and similar questions related to summarizing business operations and trends. An OLAP application that accesses data from a multidimensional database is known as a MOLAP (multidimensional OLAP) application.

A multidimensional database - or a multidimensional database management system (MDDBMS) - implies the ability to rapidly process the data in the database so that answers can be generated quickly. A number of vendors provide products that use multidimensional databases. Approaches to how data is stored and the user interface vary.