Management System Database: Hierarchical Data Model
Management System Database
A management system database consists of a set of interrelated data and a group of programs to access that data. The data set is commonly known as a database. The primary objective of a management system database is creating an environment where it is possible to store and retrieve information from the database in a convenient and efficient manner. Database systems are designed to handle large amounts of information. Data management involves both defining structures for storing information and the mechanisms for information management. In addition, the database system must maintain the security of information stored in the database, both against system crashes and against unauthorized access attempts. If data will be shared by several users, the system must avoid possible anomalous results.
Because information is important in most organizations, the database is a valuable resource. This led to the development of a large number of concepts and techniques for managing data efficiently.
Hierarchical Data Model
In the network model, information is represented by sets of records, and data relationships are represented by links. The hierarchical model is similar to the data network, and the relations between them are also represented by means of records and links, respectively. The environment relates to the network hierarchy, as the registers are organized into sets of trees instead of arbitrary graphs.
A granted hierarchical database into a set of registers connected together by a rubber band. The hierarchical model is similar to the data network, and the relations between them are also represented by records and links, respectively. The environment relates to the network hierarchy, as the registers are organized into sets of trees instead of arbitrary graphs. A granted hierarchical database into a set of registers connected together by a rubber band.
The records are similar to the network model, where a record is a set of fields (attributes), each of which contains a single value. A link is an association between two records, exclusively. So, the link concept is similar to the above model. To think of a database that represents how much a relationship-account holder in a banking system. There are two types of registration: holder and identify how much. The account holder has three fields: name, street, and city. Similarly, it has granted registration in two areas: number and balance. The set of all records and accounts of account holders is organized as a rooted tree in which the latter is a working node.
A hierarchical database consists of a set of trees of this kind, forming a forest. A tree of this class equipped with a tree root should be named database. The contents of a specific record can be repeated in several places. For example, in the banking system account holder, an account can belong to several customers. The information for the account or on account holders can belong to that will be repeated. This repetition can take place both on the same tree as the database that differs in several trees.
The repetition of records has two main disadvantages:
- There may be data inconsistency in carrying out the update.
- There will be inevitable waste of space.
Tree Structure Diagram
A tree structure diagram is the outline of a hierarchical database. Such diagram consists of two basic components: boxes that correspond to record types correspond to lines/links.