IT533 - SOFTWARE ARCHITECTURES - CLASS 3
Components can be characterized as:
An active component is a processing unit.
The processing units run the algorithms that are needed to
satisfy the functional requirements of the system.
Active components can be connected to active or passive
A passive component is a data store.
Data stores can be complex databases that are used to share
data amoung two or more components or they can be simple
files (documents) that hold data that configures or guides the
processing of an active component.
Passive components can only be connected to active components.
- Since a database system does processing, why is it a passive component?
The processes performed by a database system are related to the
storage and retrieval of data.
They do not control the processing that is required to meet
the system's functional requirements.
The active components control the database by making storage and
So, in that sense, databases are passive.
- Can two databases be directly connected?
A consequence of the answer to the previous question is that
in general, a component-and-connector view should not show a direct
connection between two databases.
But, in situations involving automatic backup or redundency,
a direct connection might be appropriate especially if the
data transfer is controlled by a component purchased from
the database vendor.
Prepared by David L. March -- Last Revised on April 9, 2003
COPYRIGHT © 2003 BY DAVID L. MARCH