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Client-Server and Distributed Data Bases - Coggle Diagram
Client-Server and Distributed Data Bases
Client-Server
client
requests to server
server
performs requests
communicates results
advantages
flexibility
easy maintaing
easy adapting
interoperability
use software and data
systems to exchange
scalability
vertical
capacity on server
horizontal
capacity on client
Architecture
Two-Tier
for systems with
stable requirements
moderate client`s number
Advantages
easy to implement
Disadvantages
difficult mainterance
rely on proprietary software
Multiple-Tier
additional layers of servers
finer processing division
improve performance
Three-Tier
improve performance
add application server
add middleware server
transaction-processing monitor
more simultaneous connections
message-oriented middleware
more flexibility in messages
Web Services
interaction between
service provider
owns service
platform offering service
service requestor
searches for service
uses service
service registry
repository
Advantages
deploy services faster
find existing services
communicate new services in standard formats
reduce electronic business`s cost
Distributed Data
Advantages
data control
available data
lower communication costs
improved performance
Global requests
combine data and transactions
update data at sites
Site
locally controlled computer
unique network address
local data managers
heterogeneous
homogeneous
complete DBMS` features
distributed data manager
uses global dictionary
coordinate local managers
controls recovery across sites
coordinates concurrency control
controls access to remote data
optimizes query
Architecture
Distributed Query Processing
local and global optimization
local optimization
global optimization
data movement
site selection decisions
Schema Architectures
fragment
vertical subset
horizontal subset
mixed fragment
allocated to one or multiple site
allocation schema
fragment`s location
fragmentation schema
fragment`s definition