Download - Session ix(database)
What is Database
A database can be defined as a collection of coherent, meaningful data.
Example: A building name A flat no in the building A road name An area name A state name
What is DBMS
DBMS is a system that allowing inserting,updating,deleting and processing of data.
Benefits of DBMS The amount of data redundancy in stored data can be
reduced. Stored data can be shared by a single or multiple users. Security of data can be simply implemented Standards can be set and followed
What is RDBMS
A RDBMS is a DBMS i.e. based on the relational model as introduced by Dr. Edgar F. Codd. Strictly speaking it should also satisfy Codd’s 12 rules, but in practice there is no DBMS that satisfies all these rules.
DBMS RDBMS
DBMS does not support C/S Architecture
Most of the RDBMS supports C/S Architecture
DBMS does not support Distributed Databases
Most of the RDBMS supports distributed databases
In DBMS there is no security of data
In RDBMS there are multiple level of security Logging in at O/S level Command Level
DBMS may satisfy less than 7 to 8 rules of Dr. E. F. Codd
RDBMS usually satisfy more than 7 to 8 rules of Dr. E. F. Codd
Normalization is a technique that:
Decomposes data into two-dimensional tables, and reduce the redundancy.
SQL is a language that provides an interface to relation database systems.
Features of SQL It is non procedural language It reduces the amount of time required for
creating and maintaining systems It is an English-like language.
DDL(Data Definition Language) DML(Data Manipulation Language) DCL(Data Control Language) DQL(Data Query Language)
DDL It is a set of SQL commands used to
create,modify and delete database structures but not data.
Example:Create,Alter,Drop,Grant,Comment
DML It is the area of SQL that allows changing data
within the database. Example:
Insert,Update,Delete,Call,Lock
DCL• It is the component of SQL statement that
control access to data and to database.• Example
Commit,Savepoint,Rollback