Specialty Databases




Several application areas for database systems are limited by the restrictions of the data model. As a result, researchers have developed several datamodels deal with these application domains, including object-based data models and
semistructured data models.

1. Object-Based Data Models

Object-oriented programming has become the dominant software-development. This led to the development of an object-oriented data model that be seen as extending the E-R model with notions of encapsulation, methods), and object identity. Inheritance, object identity, and encapsulation hiding), with methods to provide an interface to objects, are among key concepts of object-oriented programming that have found applications in modeling. The object-oriented data model also supports a rich type system, structured and collection types. In the 1980s, several database systems on the object-oriented data model were developed.
The major database vendors presently support the object-relational data, a data model that combines features of the object-oriented datamodel and data model. It extends the traditional relational model with a variety features such as structured and collection types, as well as object orientation.

2. Semistructured Data Models

Semistructured data models permit the specification of data where individual items of the same type may have different sets of attributes. This is in contrast the data models mentioned earlier, where every data item of a particular must have the same set of attributes.
The XML language was initially designed as a way of adding markup information text documents, but has become important because of its applications in exchange. XML provides a way to represent data that have nested structure, furthermore allows a great deal of flexibility in structuring of data, which is for certain kinds of nontraditional data. 



Frequently Asked Questions

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Ans: The term data mining refers loosely to the process of semi-automatically analysing large databases to find useful patterns. view more..
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Ans: The architecture of a database system is greatly influenced by the underlying computer system on which the database system runs. Database systems can be centralized, or client-server, where one server machine executes work on behalf of multiple client machines. view more..
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Ans: A transaction is a collection of operations that performs a single logical function in a database application. view more..
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Ans: Researchers have developed several data-models to deal with these application domains, including object-based data models and semi-structured data models. view more..
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Ans: A primary goal of a database system is to retrieve information from and store new information into the database. People who work with a database can be categorized as database users or database administrators. view more..
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Ans: Information processing drives the growth of computers, as it has from the earliest days of commercial computers. In fact, automation of data processing tasks predates computers. view more..
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Ans: A relational database consists of a collection of tables, each of which is assigned a unique name. view more..
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Ans: The database schema is the logical design of the database. view more..
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Ans: A super-key is a set of one or more attributes that, taken collectively, allow us to identify uniquely a tuple in the relation. view more..
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Ans: DBMS typically includes a database security and authorization subsystem that is responsible for ensuring the security of portions of a database against unauthorized access view more..
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Ans: The typical method of enforcing discretionary access control in a database system is based on the granting and revoking of privileges. Let us consider privileges in the context of a relational DBMS. view more..
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Ans: This chapter discusses techniques for securing databases against a variety of threats. It also presents schemes of providing access privileges to authorized users. view more..
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Ans: This chapter discusses techniques for securing databases against a variety of threats. It also presents schemes of providing access privileges to authorized users. view more..
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Ans: Object databases is the power they give the designer to specify both the structure of complex objects and the operations that can be applied to these objects view more..
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Ans: XML (Extensible Markup Language)—has emerged as the standard for structuring and exchanging data over the Web. XML can be used to provide information about the structure and meaning of the data in the Web pages rather than just specifying how the Web pages are formatted for display on the screen view more..
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Ans: A database schema, along with primary key and foreign key dependencies, can be depicted by schema diagrams. view more..
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Ans: A query language is a language in which a user requests information from the database. view more..
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Ans: All procedural relational query languages provide a set of operations that can be applied to either a single relation or a pair of relations. view more..




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