Distributed Database Management Systems: Lecture 9

Distributed Database Management Systems: Lecture 9. The main topics covered in this chapter include: networks continued, DDBMS architecture; local area network; metropolitan area network; wide area network; maintained during conversation;...

Distributed Database Management Systems

Lecture 09

In the previous lecture

Algebra Ops…

In this Lecture

Scale

• Local Area Network

• Metropolitan Area Network

• Wide Area Network

• Can be Broadcast and Point

to Point

• In Point to Point

–Circuit Switching

–Packet Switching

Packet Switching

routes

Advantages of Packet Switching

• Better Link Utilization

• Bursty Nature of

communication

• Parallel transmission

MANs

Protocol Standards

Set of rules and formats for exchanging data,

arranged into layers

called protocol suite/

stack

• WAN faces max

heterogeneity

• Protocols between

corresponding layers

at different sites

form Comm subnet

Distributed DBMS

Architecture

Architecture of a

systems defines its structure

Sheth, A P., Larson, J A., ‘ Federated Database

Systems for Managing

Distributed Heterogeneous, and Autonomous

Databases’, ACM

Computing Surveys, 22, No

3, p(183-236), Sep., 90

• Three major (idealized)

architectures of DDBMS discussed

–Peer to peer

–Client/Server

–Multidatabase

• Component-based

Practically

• Every aspect has to be considered

• These Classification schemes are

Orthogonal

• A committee for the task

established in 1972 by ANSI under SPARC

• Published standard in 1977

Reference Model

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Conceptual     View

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