1. Object Relational DBMSs
Presented By:
Sajida Hayek

2. Outline Why ORDBMS? What is ORDBMS? Stonebreaker’s view
Advantages and disadvantages of ORDBMS
Object-Relational Operations
Object-Relational Mapping

3. Why ORDBMS

4. What is ORDBMS?
Systems that attempt to extend relational database systems with the functionality necessary to support a broader class of applications and, in many ways, provide a bridge between the relational and object-oriented paradigms.

5. Stonebraker’s View

6. Advantages of ORDBMSs Resolves many of known weaknesses of RDBMS.
Reuse and sharing
Preserves significant body of knowledge and experience gone into developing relational applications.

7. Disadvantages of ORDBMSs
Complexity.
Increased costs.
Simplicity and purity of relational model are lost.

8. Object-Relational Operations: CRUD
Common OR operations:
Create - save (persist) a new object in the database
Retrieve an object from the database
Update data for an object already saved in database
Delete object's data from the database

9. Object-Relational Mapping (ORM)
A software system that shuttles data back and forth between database rows and objects
Appears as a normal database user to the database
Can share the database and tables with other apps
Object-intensive app
Database
Other apps
ORM

10. Object-Relational Mapping Cont.
Map between an object and a row in a database table.
Location
id: int
name: String
address: String
Class
should have an identifier attribute
Data Mapper
convert object to table row data, convert data types, instantiates objects
Data Mapper
LOCATIONS
PK id INTEGER
name VARCHAR(80)
address VARCHAR(160)
Database Table
identifier is usually the primary key of table

11. Mapping an Object ku : Location id = 101 name = "Kasetsart University"
address = "90 Pahonyotin ..."
object diagram
save( )
LOCATIONS
id name address
101 Kasetsart University 90 Pahonyotin ...
102 Seacon Square 120 Srinakarin ...

12. Thank You ☺