IBM BS029ML - WebSphere Portal Server Self Help Manual page 33

information systems. A modification of the product information on one EIS triggers a business
application that processes the data and propagates it to the other enterprise information
systems.
LDAP Directory Server
A directory is often described as a database, but it is in fact a specialized database that has
unique characteristics that set it apart from that of general purpose relational databases. One
special characteristic of directories is that they are accessed (read or searched) much more
often than they are updated (written). Hundreds of people might look up an individual's phone
number, or thousands of print clients might look up the characteristics of a particular printer,
but the phone number or printer characteristics rarely ever change.
Database Server
The Database Server's function is to provide persistent data storage and retrieval in support
of the user-to-business transactional interaction. The data stored is relevant to the specific
business interaction, for example, bank balance, insurance information, current purchase by
the user, and so on.
Portlet applications
Portlets are a central part of WebSphere Portal Server. Portlets are small Portal applications
that are independently developed, deployed, managed, and displayed. Portlets have multiple
states and view modes, plus event and messaging capabilities. Portlets run inside the Portlet
container of WebSphere Portal Server, similar to the way a servlet runs on a WebSphere
Application Server. The Portlet container provides a runtime environment where Portlets are
instantiated, used, and finally destroyed. Portlets rely on the WebSphere Portal Server
infrastructure to access user profile information, participate in window and action events,
communicate with other Portlets, access remote content, look up credentials, and store
persistent data.
J2EE Enterprise Applications
An Enterprise Application is a J2EE deployment unit that bundles together Web Applications,
EJBs, and Resource Adaptors into a single deployable unit.
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Chapter 2. Architecture and planning