CLASSIFICATION ACCORDING TO DATA MODELS Hierarchal Model In a hierarchical data model, data are organized into a tree-like structure. Network Model based on an enlargement of the concept of hierarchical data bases. Relational Model Data are stored in tables Object Oriented model Object oriented data base systems are the most recent development in data base technology. Introduction Definations Advantages and Disadvantages PowerPoint Presentation PowerPoint Presentation for free

1. DBMS CLASSIFICATION
ACCORDING TO DATA
MODELS
ABDUL KHALIQ (abdulkhaliq005gis@gmail.com)

2. CLASSIFICATION ACCORDING TO DATA MODELS
Hierarchal Model
Network Model
Relational Model
Object Oriented model

3. Hierarchical Model
In a hierarchical data
model, data are organized
into a tree-like structure.
Use parent/child
relationships:
• each parent can have many
children but
• each child only has one parent.
• This is called one to many (1:N)
relationship

4. • Hierarchical Model is simple to construct and
operate on
• Corresponds to a number of natural
hierarchically organized domains - e.g.,
assemblies in manufacturing, personnel
organization in companies
• Language is simple; uses constructs like GET, GET
NEXT, GET NEXT WITHIN PARENT etc.
ADVANTAGES:
• Navigational and procedural nature of
processing
• Database is visualized as a linear arrangement of
records
• Little scope for "query optimization"
DISADVANTAGES:

5. Network Model
based on an
enlargement of the
concept of hierarchical
data bases.
Instead of one single
hierarchy, several
hierarchical access
paths can be provided.
In this way,
redundancy in the
data can be avoided.
In contrast to
hierarchical data base
models
• one child node can have
more than one father
node.
Access via the pointers
of the network is quite
fast whereas access
via other attributes
becomes inefficient.

6. • Network Model is able to model complex relationships and
represents semantics of add/delete on the relationships.
• Can handle most situations for modeling using record types and
relationship types.
• Language is navigational; uses constructs like FIND, FIND
member, FIND owner, FIND NEXT within set, GET etc.
Programmers can do optimal navigation through the database.
ADVANTAGES:
• Navigational and procedural nature of processing
• Database contains a complex array of pointers that thread
through a set of records.
Little scope for automated "query optimization
DISADVANTAGES:

7. Relational Model
(RDBMS)
Data are stored in tables.
Its rows contain objects of identical type;
Columns describe the attributes of each of the instances of the object.
Queries to a relational data base are formulated in a query language, for instance in SQL
(Structure Query Language).
Tables can be modified or combined by several operations of relational algebra

8. • Data base queries are based on a comparison of the table
contents.
• The tables are independent and not related by pointers. That is
why it is easy to maintain dynamic data sets.
• The tables can be easily expanded by new columns.
• It is easy to create user specific views from relational data bases.
Advantages
• Slower access rates compared to hierarchical or network based
data bases. Faster access rates can be achieved by the indexing
techniques which, however, require additional disk space.
• Access to spatial data by geometrical attributes is not optimal.
Disadvantages

9. Object Oriented Model
(ODBMS)
Object oriented data base systems are the most recent development in data base technology.
Goal: to offer more complex data
Define a database in terms of object
• Objects are consist of properties and operations (procedures)
• Objects with same property and operation are belong to one class
• Classes are organized into hierarchies
Extends Relational Model to include
• Objects / Structured Type
• Methods defined for object
• Ability of one tuple to refer to another through reference type

10. • The object-oriented data model allows the 'real
world' to be modeled more closely.
• It new data types to be built from existing types.
• The tight coupling between data and applications in
an OODBMS makes schema evolution more feasible.
Advantages
• There is a general lack of standards of OODBMS.
• Query optimization requires.Disadvantages