Programmeerimiskeel
Sissejuhatus informaatikasse
18
Repository Style
•Characterized by
.a central data store component-system states
.a collection of independent components operating on the data
store
•Advantage
.Well suited for applications with changing services
.Once a repository is defined, new services can be added
•Disadvantage
.The repository can become a bottleneck
.Modified repository-subsystems may be modified
ITK 2007, Kalev Pihl
Sissejuhatus informaatikasse
19
Blackboard (Repositoty style)
•Data store state triggers
processes
ITK 2007, Kalev Pihl
Sissejuhatus informaatikasse
20
shared memory
agent
agent
agent
State
computation
Two-Tier Client server (Repository
style)
.Developed to decouple user interface
from data storage
.Leads to improved maintainability
(changes to UI and database can be made
independently
.Characteristics of a server:
.Passive (slave)
.Waits for requests
.Upon receipt of requests, processes them and
then serves replies
annaabi.ee 
