2-Tier,3-Tier datawarehouse Submitted by Manisha Dubey & Akanksha Agrawal

2 tier Architecture A two tier architecture is simply based on client-server architecture. A 2-tier architecture is one which has a client tier, and a database tier. –The database tier manages the database –The client tier is the interface between the user and the system

2 tier Architecture

The Client Tier The first tier(Client tier)is the front-end clie nt layer. This layer holds the following tools query tools reporting tools analysis tools data mining tools

The Database Server Tier The second tier(Database server) is the b ottom tier of the architecture datawareho use database server It is the relational database system We use the back end tools and utilities to feed data into the bottom tier These backend tools and utilities perform the extract, clean, load, and refresh functions

Benefits and Limitation of 2-Tier Architecture Benefits –great for creating applications quickly using visual builder tools thanks to its simplicity –appropriate to departmental applications e.g.) decision support, small-scale groupware, simple web-based applications Limitations –not mission-critical, not scalable

GUI SQL, File Server, HTTP protocol Tier 1 Tier 2 Database(or Other Resource Managers) A 2-Tier Client-Server Application Architecture Tier 3 RPCs, Conversations, Queues, Publish-and-Subscribe, Broadcasts, Object invocations GUI Tier 2 Tier 1 Application Database(or Other Resource Managers) A 3-Tier Client-Server Application Architecture

Why 3-Tier Architecture ? Needs of new world’s applications –Business will increasingly compete be being the first to market with new electronic goods and services –Companies will create virtual corporations through alliances with a shifting set of partners –Roles and relationships btw. enterprises will shift frequently as industries realign

Why 3-Tier Architecture ? Reasons –Meets the requirements of large-scale internet and intranet client/server applications –Is easier to manage and deploy on the network most of code runs on the servers, especially with zero-footprint technologies like Java applets –Minimizes network interchanges by creating abstract levels of service –Provides better security by not exposing the database schema to the client by enabling more fine-grained authorization on the server

 It was developed by John J. Donovan in Open Environment Corporation (OEC), a tools company he founded in Cambridge, Massachusetts  A three tier architecture typically consist of – Presentation tier Domain logic tier Data storage tier 3-Tier Architecture

Get sales total Total sales Get list of all sales made last year Query Add all sales togeather Sales 1 … Presentation tier Logic tier Data tier database storage

Three-tier architecture is a client–server architecture in which the user interface( presentation ), functional process logic ("business rules"), computer data storage and data access are developed and maintained as independent modules, most often on separate platforms. 3-Tier Architecture

 This is the topmost level of the application.  The presentation tier displays information related to such services as browsing merchandise, purchasing and shopping cart contents.  It communicates with other tiers by which it puts out the results to the browser/client tier and all other tiers in the network. (In simple terms it is a layer which users can access directly such as a web page, or an operating systems GUI)

The logical tier is pulled out from the presentation tier and, as its own layer, it controls an application’s functionality by performing detailed processing.

 The data tier includes the data persistence mechanisms (database servers, file shares, etc.)  The data access layer that encapsulates the persistence mechanisms and exposes the data.  The data access layer should provide an Application Programming Interface (API) to the application tier that exposes methods of managing the stored data without exposing or creating dependencies on the data storage mechanisms.