Showing posts with label Date's 12 Rules. Show all posts
Showing posts with label Date's 12 Rules. Show all posts

Date's Tweleve Rules for Distributed Database Systems - Database (DBMS) Independence

Date's Tweleve Rules for Distributed Database Systems - Database [DBMS] Independence


DBMS independence

The system must support any vendor's database product. The DBMS instances at different sites all support the same interface - they do not necessarily all have to be copies of the same DBMS software. The ideal distributed system should be heterogeneous and should provide DBMS independence.
For example, if Ingres and Oracle both supported the official SQL standard, the Ingres site and the Oracle site might be able to talk to each other in a distributed database system. Pictorial representation of the same is given below.


Fig 1 - Distributed database with database independence (source: Prof. Sin Min Lee ppt from CJ Date book)








Date's Tweleve Rules for Distributed Database Systems - Network Independence

Date's Tweleve Rules for Distributed Database Systems - Network Independence


The system should not depend on particular network implementations and protocols.

Network Independence rule can be defined in different way as follows;


  • Desirable to be able to support a variety of disparate communication networks also.
  • Network independence: The DDB and its associated DDBMS should be capable of being implemented on any suitable network platform. 

    Note:  At present, this goal means that the DDBMS should be able to run on Windows NT, on Windows 2000, on any variant of Unix, and on Novell Networks. 
  • A distributed database system should be designed to run regardless of the communication protocols and network topology used to interconnect various system nodes.





Date's Twelve Rules for Distributed Database Systems - Hardware Independence


Date's Twelve Rules for Distributed Database Systems - Hardware independence / DDBS should support different hardware architectures

It should be possible to run the DDBMS on a variety of hardware platforms.

The DDB and its associated DDBMS should be capable of being implemented on any suitable platform, i.e., on any computer with appropriate hardware resources regardless of what company manufactured the computer.

Any truly distributed DBMS system should not rely on a particular hardware feature, nor should it be limited to a certain hardware architecture or vendor.

Refer the following figure. In this figure, Chennai site is configured with x86 server platforms, Mumbai site is configured with Intel IA64 server platforms, and New Delhi site is configured with SPARC_64 server architecture. Irrespective of hardware and platforms, the distributed database system has to work with all architectures.
Figure - Hardware independence

Real world involves a multiplicity of different machines—IBM machines, HP machines, PCs and workstations of various kinds. This is one of the major reasons for hardware independence rule in Distributed databases.