ADVANTAGES AND DISADVANTAGES OF VARIOUS DATABASE MODELS

File system
1st Generation
1960s-1970s
Used mainly on IBM mainframe systems
Managed records, not relationships
Hierarchical DBM Data Independence?
Yes
Hierarchical DBM Structural Dependence?
No
Hierarchical and Network DBMs – what generation, when introduced and improvements to prior generations….
2nd Generation
1970
Early database systems
Navigational access
Hierarchical DBM advantages
1. It promotes data sharing.
2. Parent/child relationship
promotes conceptual simplicity.
3. Database security is provided
and enforced by DBMS.
4. Parent/child relationship
promotes data integrity.
5. It is efficient with 1:M
relationships.
Hierarchical DBM disadvantages
1. Complex implementation requires knowledge of physical data storage characteristics.
2. Navigational system yields complex application development, management, and use; requires knowledge of hierarchical path.
3. Changes in structure require changes in all application programs.
4. There are implementation limitations (no multiparent or M:N relationships).
5. There is no data definition or data manipulation language in the DBMS.
6. There is a lack of standards.
Network
Yes
Relational
Yes
– what generation, when introduced and improvements to prior generations….
3rd Gen
Mid-1970s
Conceptual simplicity
Entity relationship (ER) modeling and support for relational data modeling
entity relationship (ER) model, or ERM,
1976
Peter Chen
has become a widely accepted standard for data modeling
Entity relationship
Yes
Object oriented
Yes
XML Hybrid
5th Gen
Mid-1990s
Unstructured data support
O/R model supports XML documents
Hybrid DBMS adds object front end to relational databases
Support large databases (terabyte size)
Key-value store
Column store
Emerging Models: NoSQL
Early 2000s to present
Distributed, highly scalable
High performance, fault tolerant
Very large storage (petabytes)
Suited for sparse data
Proprietary application programming interface
(API)
NoSQL
Yes
SimpleDB (Amazon)
BigTable (Google)
Cassandra (Apache)
MongoDB
Riak
Key-value store
Column store
No SQL
DB2
Relational DBM
Oracle
Relational DBM
MS SQL Server
MySQL
Relational DBM
Oracle 12c
XML Hybrid DBMS
Object-oriented
Object/relational (O/R)
MS SQL Server
XML Hybrid DBMS