Data
Unanalyzed raw facts, figures, objects and events said called as Data.
Information
Process of the data are called Information.
Database
A database is a collection of related information. A database is a logically coherent collection of data with some inherent meaning.
DBMS
Database Management system is a collection of programs that enables user to create and maintain a database.
Thus a DBMS is a general purposed s/w system that facilitates the process of defining constructing and manipulating a database for various applications. (Defining a data base involves specifying the data types, structures and constraints for the data to be stored in the data database.
Constructing a data base is the process of storing data itself on some storage medium that is controlled by DBMS. Manipulating a database includes such functions as querying the data base to retrieve specific data, updating the database to reflect the changes in the mini-world.
Database Management system is a collection of programs that enables user to create and maintain a database.
Thus a DBMS is a general purposed s/w system that facilitates the process of defining constructing and manipulating a database for various applications. (Defining a data base involves specifying the data types, structures and constraints for the data to be stored in the data database.
Constructing a data base is the process of storing data itself on some storage medium that is controlled by DBMS. Manipulating a database includes such functions as querying the data base to retrieve specific data, updating the database to reflect the changes in the mini-world.
Catalog
A catalog is a table that contain the information such as structure of each file, the type and storage format of each data item and various constraints on the data. The information stored in the catalog is called Metadata . Whenever a request is made to access a particular data, the DBMS s/w refers to the catalog to determine the structure of the file.
A catalog is a table that contain the information such as structure of each file, the type and storage format of each data item and various constraints on the data. The information stored in the catalog is called Metadata . Whenever a request is made to access a particular data, the DBMS s/w refers to the catalog to determine the structure of the file.
Data Warehousing and OLAP
Data warehousing and OLAP (online analytical processing ) systems are the techniques used in many companies to extract and analyze useful information from very large databases for decision making .
Data warehousing and OLAP (online analytical processing ) systems are the techniques used in many companies to extract and analyze useful information from very large databases for decision making .
Real Time Database Technology
These are all the techniques used in controlling industrial and manufacturing processes.
These are all the techniques used in controlling industrial and manufacturing processes.
Program-Data Independence
Unlike in the traditional file sys. the structure of the data files is stored in the DBMS catalog separately from the access programs . This property is called program-data independence i.e. We needn’t to change the code of the DBMS if the structure of the data is changed. Which is not supported by traditional file sys .
Unlike in the traditional file sys. the structure of the data files is stored in the DBMS catalog separately from the access programs . This property is called program-data independence i.e. We needn’t to change the code of the DBMS if the structure of the data is changed. Which is not supported by traditional file sys .
ORDBMS
Object oriented RDBMS is a relational DBMS in which everything is treated as objects. User can define operations on data as a part of the database definition.
Object oriented RDBMS is a relational DBMS in which everything is treated as objects. User can define operations on data as a part of the database definition.
Program-Operation Independence
An operation is specified in two parts .
a) Interface (operation name and data types of its arguments).
b) Implementation (the code part)
The implementation part can be changed without affecting the interface. This is called
program-operation independence.
An operation is specified in two parts .
a) Interface (operation name and data types of its arguments).
b) Implementation (the code part)
The implementation part can be changed without affecting the interface. This is called
program-operation independence.
View
A view may be a subset of the database or it may contain virtual data that is derived from the database files but is not explicitly stored .
A view may be a subset of the database or it may contain virtual data that is derived from the database files but is not explicitly stored .
OLTP
Online transaction processing is an application that involve multiple database accesses from different parts of the world . OLTP needs a multi-user DBMS s/w to ensure that concurrent transactions operate correctly.
Online transaction processing is an application that involve multiple database accesses from different parts of the world . OLTP needs a multi-user DBMS s/w to ensure that concurrent transactions operate correctly.
DBA
A database administrator is a person or a group responsible for authorizing access to the database, for coordinating and monitoring its use, and for acquiring s/w and h/w resources as needed.
A database administrator is a person or a group responsible for authorizing access to the database, for coordinating and monitoring its use, and for acquiring s/w and h/w resources as needed.
DB Designer
base and for choosing appropriate structure to represent and store this data .Data base designers are responsible for identifying the data to be stored in the data
base and for choosing appropriate structure to represent and store this data .Data base designers are responsible for identifying the data to be stored in the data
Different types of End users
a) Casual end-users
b) Naive or parametric end users
c) Sophisticated end users
d) Stand alone users.
a) Casual end-users
b) Naive or parametric end users
c) Sophisticated end users
d) Stand alone users.
Aadvantages of using a DBMS
a) Controlling redundancy.
b) Restricting unauthorized access.
c) Providing persistent storage for program objects and data structures.
d) Permitting inferencing and actions using rules.
e) Providing multi-user interfaces.
f) Representing complex relationships among data.
a) Controlling redundancy.
b) Restricting unauthorized access.
c) Providing persistent storage for program objects and data structures.
d) Permitting inferencing and actions using rules.
e) Providing multi-user interfaces.
f) Representing complex relationships among data.
g) Enforcing integrity constraints.
h)Providing backups and recovery.
h)Providing backups and recovery.
Disadvantages of using a DBMS
a) High initial investments in h/w, s/w, and training.
b) Generality that a DBMS provides for defining and processing data.
c) Overhead for providing security, concurrency control, recovery, and integrity functions.
a) High initial investments in h/w, s/w, and training.
b) Generality that a DBMS provides for defining and processing data.
c) Overhead for providing security, concurrency control, recovery, and integrity functions.
Data Model
It is a collection of concepts that can be used to describe the structure of a database. It provides necessary means to achieve this abstraction. By structure of a database we mean the data types, relations, and constraints that should hold on the data.
Categories of Data Models
a) High-level or conceptual data models.
b) Representational data models.
a) High-level or conceptual data models.
b) Representational data models.
c) Low-level or physical data models.
High level data models provide the concepts that are close to the way many users perceive data.
Representational data models are provide concepts that provide the concepts that may be understood by end users but that are not too far removed from organization of data in the database.
Physical data models describe the details of how data is stored in the computers.
High level data models provide the concepts that are close to the way many users perceive data.
Representational data models are provide concepts that provide the concepts that may be understood by end users but that are not too far removed from organization of data in the database.
Physical data models describe the details of how data is stored in the computers.
Schema
The description of a data base is called the database schema , which is specified during database design and is not expected to change frequently . A displayed schema is called schema diagram .We call each object in the schema as schema construct.
The description of a data base is called the database schema , which is specified during database design and is not expected to change frequently . A displayed schema is called schema diagram .We call each object in the schema as schema construct.
No comments:
Post a Comment