What and why ORDBMS, advantages, disadvantages, operations and mappings.

1. Object Relational DBMS
Presented by:
Gagan Puri
Bikram Bhurtel
Anjil Shakya
Rabin BK
BSc.CSIT 4th Semester 1

2. Content
• Merging relational and object models
• Why ORDBMS?
• What is ORDBMS?
• Stonebreaker’s view
• Advantages and disadvantages of ORDBMS
• Object-Relational Operations
• Object-Relational Mapping
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3. Merging Relational and Object Models
Object-oriented models support interesting data types --- not
just flat files.
– Maps, multimedia, etc.
The relational model supports very-high-level queries.
Object-relational databases are an attempt to get the best of
both.
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4. Evolution of ORDBMS
Object-oriented DBMS’s failed because they did not offer the
efficiencies of well-entrenched relational DBMS’s.
Object-relational extensions to relational DBMS’s capture
much of the advantages of Object Oriented, yet retain the
relation as the fundamental abstraction.
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5. Why ORDBMS?
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6. What is ORDBMS?
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• Systems that attempts 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
• This system supports objects, classes and inheritance in
database schemas and query language

7. Stonebraker’s View
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8. Charaterstics of ORDBMS
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• Complex data
• Type inheritance
• Object behavior

9. 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
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10. Disadvantages of ORDBMS
• Complexity.
• Increased costs.
• Simplicity and purity of relational model are lost.
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11. Object-Relational (OR) Operations
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
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12. Object-Relational Mapping (ORM)
• A programming technique for converting data between
incompatible type systems using object-oriented programming
languages
• This creates, in effect, a "virtual object database" that can be used
from within the programming language
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Object-intensive
app
Database
Other apps
ORM
• Appears as a normal database
to the database user
• Can share the database and
tables with other apps

13. Object-Relational Mapping Contd...
• Map between an object and a row in a database table.
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• Database Table
– identifier is usually the primary
key of table
• Data Mapper
– a Data Access Layer
– performs bidirectional transfer of
data between a persistent data
store (often a relational database)
and an in-memory data
representation (the domain layer)
LOCATIONS
PK id INTEGER
name VARCHAR(80)
address VARCHAR(160)
Location
id: 101
name: Sherlock Holmes
address: 221 Baker Street
Data
Mapper
OOP (domain layer)
Relational database

14. Mapping an Object
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LOCATIONS
id name address
101 Sherlock Holmes 221B Baker Street ...
102 Dr. Watson 224B Baker Street ...
Detective's : Location
id = 101
name = "Sherlock Holmes"
address = "221B Baker Street ..."
object diagram
save( )

15. Conclusion
• Aims to bridge the gap between conceptual data modeling
techniques for relational and object-oriented databases like the
entity-relationship diagram (ERD) and object-relational mapping
(ORM)
• Aims to connect the division between relational databases and the
object-oriented modeling techniques that are usually used in
programming languages like Java, C# and C++.
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16. References
https://www.techopedia.com/definition/8714/object-relational-
database-ord
http://www.informit.com/articles/article.aspx?p=1216889
https://www.techopedia.com/definition/24081/database-object
https://docs.oracle.com/cd/B19306_01/server.102/b14200/sql_e
lements007.htm
https://www.geeksforgeeks.org/dbms-database-objects/
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17. Any Queries
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