2.Components Of DBMS
3.Types of Database
List of OnLine DB's
A database consists of an organized
collection of data.
Digital databases are managed using
database management systems, which
store database contents, allowing data
creation and maintenance, and search and
2.Components Of DBMS:
Most DBMS as of 2009 implement a relational model.
Sublanguages DDL, DCL, DML.
SQL engine, Transaction engine, Relational engine,
ODBMS handle DDL, DCL and update tasks
differently. Instead of using sublanguages, they provide
APIs for these purposes.
Example object query languages are OQL, LINQ,
JDOQL, JPAQL and others.
The query engine returns collections of objects instead
of relational rows.
3.Types of Database:
operational DB Distributed DB
Datawarehouse End_User DB
Analytical DB External DB
Postrelational database models
Products offering a more general data
model than the relational model are
sometimes classified as Postrelation.
Object database models
object databases attempt to introduce
key ideas of object programming, such
as envapsulation and Polymorphism,
into the world of databases.
Databases may store relational
tables/indexes in memory or on hard disk in
one of many forms:
ordered/unordered flat files
Indexing is a technique for improving database
In large databases, this can reduce query time/cost by
orders of magnitude.
DBMS provide some form of support for
Itallow multiple data items to be updated in a
1.Atomicity: Either all the data changes in a
transaction must happen, or none of them.
2.Consistency: Every transaction must be
3.Isolation:Two concurrent transactions cannot
interfere with one another
4.Durability:Completed transactions cannot be
Replication involves maintaining multiple copies of a
database on different computers, to allow more users to
DBMSs usually enforce security through access
control, auditing, and encryption.
Locks also provide one method of ensuring that data
does not change while a transaction that once read it
An online database is a database accessible from a
network, including from the Internet.
Some differences from typical traditional databases
such as Oracle, Microsoft SQL Server, Sybase..etc
(i)These online databases are delivered primarily via a
web browser .
(ii)They are often purchased by a monthly subscription
(iii)They embed common collaboration features such as
sharing, email notifications, etc.
Open source Databases for “CONTENT
MANAGEMENT SYSTEM ”
What Open Source Databases are there?
Most widely used OSDB
Very fast read access, good for web apps
SQL interface, ODBC, JDBC
C, C++, Perl, Python, TCL
Open source spatial databases (PostGIS) are new,
but are already in use around the world.
Many GIS database problems can now realistically
be addressed with open source technology
Open source databases have the capabilities to
handle real world problems, and are in widespread