Database Management System can be classified on several DBMS criteria.
A) On the Basis of Data Models.
Data model is a collection of high level data description that hides many low level storage details. A data Model has following three Components:
1) A Structural Part that consist of a set of rules according to which database is constructed.
2) A Manipulating Part That defines type of operations that are allowed on data.
3) A set of integrity rules that ensures that data is correct.
The Data Models are further divided into Three Categories:
1) A Structural Part that consist of a set of rules according to which database is constructed.
2) A Manipulating Part That defines type of operations that are allowed on data.
3) A set of integrity rules that ensures that data is correct.
The Data Models are further divided into Three Categories:
I) Object Base Data Models: Object based data models defines a database in terms of objects, their properties, and their operations .Objects of same behavior and structure belongs to a class and classes are organized into hierarchies. The operations of each class are specified in terms of predefined procedures called methods. Commonly used object based data models are:
Entity Relationship, Object Oriented, Semantic, Functional
II) Physical Data Models: Physical data models include all data artifacts that are required to create relationship between tables or to achieve performance goals, such as indexes, constraint definitions, Linking tables partition tables or clusters.
III) Record Based Models: These models are used to specify overall logical structure of database and to provide a higher level description of the implementation. There are 3 types of record based data models:-Hierarchical Data Models, Network Data Models, Relational data Models.
Entity Relationship, Object Oriented, Semantic, Functional
II) Physical Data Models: Physical data models include all data artifacts that are required to create relationship between tables or to achieve performance goals, such as indexes, constraint definitions, Linking tables partition tables or clusters.
III) Record Based Models: These models are used to specify overall logical structure of database and to provide a higher level description of the implementation. There are 3 types of record based data models:-Hierarchical Data Models, Network Data Models, Relational data Models.
B) On the Basis of Users
A second criterion on which database management is classified is the no. of users supported by system.
I) Single User Data Models: This data model supports only one user at a time and is mostly used with PCs.
II) Multiuser Data Models: This type of data model support concurrent access of database to multiple users.
II) Multiuser Data Models: This type of data model support concurrent access of database to multiple users.
C) On the Basis of Site Location
I) Centralized Database Model: In this DBMS model data is stored centrally on a single computer site. DBMS can support multiple users but DBMS and database both resides totally on a single computer site.
II) Distributed DBMS: This Model contains actual database and DBMS software distributed over many sites, connected by a computer network
II) Distributed DBMS: This Model contains actual database and DBMS software distributed over many sites, connected by a computer network
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