Components of DDBMS, Computer workstations or remote devices,Network hardware and software components,Communications media,transaction processor (TP), data processor (DP),

1. Prof. Neeraj Bhargava
Pooja Dixit
Department of Computer Science
School of Engineering & System Science
MDS, University Ajmer, Rajasthan, India
1

2.  The different components of DDBMS are as follows:
 Computer workstations or remote devices (sites or nodes)
that form the network system. The distributed database
system must be independent of the computer system
hardware.
 Network hardware and software components that reside in
each workstation or device. The network components allow
all sites to interact and exchange data. Because the
components—computers, operating systems, network
hardware, and so on—are likely to be supplied by different
vendors, it is best to ensure that distributed database
functions can be run on multiple platforms.
 Communications media that carry the data from one node to
another. The DDBMS must be communications media-
independent; that is, it must be able to support several types
of communications media.
2

3.  The transaction processor (TP), which is the software
component found in each computer or device that
requests data. The transaction processor receives and
processes the application’s data requests (remote and
local). The TP is also known as the application processor
(AP) or the transaction manager (TM).
 The data processor (DP), which is the software
component residing on each computer or device that
stores and retrieves data located at the site. The DP is
also known as the data manager (DM). A data processor
may even be a centralized DBMS.
 The following Figure illustrates the placement of the
components and the interaction among them. The
communication among TPs and DPs shown in the figure
is made possible through a specific set of rules, or
protocols, used by the DDBMS.
3

4. 4
The protocols determine how the distributed database system will:
 Interface with the network to transport data and commands between data
processors (DPs) and transaction processors (TPs).
 Synchronize all data received from DPs (TP side) and route retrieved data to
the appropriate TPs (DP side).
 Ensure common database functions in a distributed system. Such functions
include security, concurrency control, backup, and recovery.
Here each TP can access data on any DP, and each DP handles all requests for local data from any TP.