Types dbms
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This document describes four types of databases: hierarchical, network, relational, and object-oriented. Hierarchical databases organize data in a tree structure with parent-child relationships. Network databases use a many-to-many relationship structure like a graph. Relational databases organize data into tables with rows and columns. Object-oriented databases store reusable software objects that contain data and instructions.
Types dbms
- 1. DBMS
- 2. TYPES OF DATABASES Hierarchical database Network database Relational database Object-oriented database
- 3. HIERARCHICAL DATABASE A DBMS is said to be hierarchical if the relationships among data in the database are established in such a way that one data item is present as the subordinate of another one. Here subordinate means that items have 'parent- child' relationships among them. Direct relationships exist between any two records that are stored consecutively. The data structure "tree" is followed by the DBMS to structure the database. No backward movement is possible/allowed in the hierarchical database.
- 4. NETWORK DATABASE A DBMS is said to be a Network DBMS if the relationships among data in the database are of type many-to-many. The relationships among many-to-many appears in the form of a network. Thus the structure of a network database is extremely complicated because of these many-to-many relationships in which one record can be used as a key of the entire database. A network database is structured in the form of a graph that is also a data structure.
- 5. RELATIONAL DATABASE A DBMS is said to be a Relational DBMS or RDBMS if the database relationships are treated in the form of a table. there are three keys on relational DBMS 1)relation 2)domain 3)attributes. A network means it contains fundamentel constructs sets or records.sets contains one to many relationship,records contains fields statical table that is composed of rows and columns is used to organize the database and its structure and is actually a two dimension array in the computer memory. A number of RDBMSs are available, some popular examples are Oracle, Sybase, Ingress,Informix, Microsoft SQL Server, and Microsoft Access.
- 6. OBJECT-ORIENTED DATABASE Object-oriented databases use small, reusable chunks of software called objects. The objects themselves are stored in the object-oriented database. Each object consists of two elements: 1) a piece of data (e.g., sound, video, text, or graphics), and 2) the instructions, or software programs called methods, for what to do with the data. Object-oriented databases have two disadvantages. First, they are more costly to develop. Second, most organizations are reluctant to abandon or convert from those databases that they have already invested money in developing and implementing. However, the benefits to object-oriented databases are compelling. The ability to mix and match reusable objects provides incredible multimedia capability.
- 7. OBJECT-ORIENTED DATABASE Object-oriented databases use small, reusable chunks of software called objects. The objects themselves are stored in the object-oriented database. Each object consists of two elements: 1) a piece of data (e.g., sound, video, text, or graphics), and 2) the instructions, or software programs called methods, for what to do with the data. Object-oriented databases have two disadvantages. First, they are more costly to develop. Second, most organizations are reluctant to abandon or convert from those databases that they have already invested money in developing and implementing. However, the benefits to object-oriented databases are compelling. The ability to mix and match reusable objects provides incredible multimedia capability.