In the field of Information Technology, DBMS architecture can be defined as integrated combination of security standards for setting as well as programming aspect of databases along with the functioning or operating mechanism of existing structures. Architecture mainly focuses on the overall design and construction of database for large enterprise database systems that so as to manage massive amounts of information for organizations. DBMS Architecture helps in design, development, implementation, and maintenance of a database to great extent. To understand database architecture, we must understand how users of modern day applications interact with information stored in large enterprise environmental settings.
As we’re known to the fact that most users of a database system today are not present at the site of system that’re using them. Databases are connected to it through computer network. Remote machines on which database user work can be referred to as client machines. On the other hand, database system runs on machines called as servers. On the basis of design of system, DBMS architecture can be of either Centralized or Decentralized or Hierarchical type. Whatever it be, DBMS architecture can be seen as either a single-tier or multi-tier. Number of tiers depends upon the specific application requirements or how organizations implement their business logic.
There’re mainly 3 types of DBMS architectures:
1. Single/One Tier (1-Tier)
2. Two Tier Architecture (2-Tier)
3. Three Tier Architecture (3-Tier)
Single Tier database architecture is a simplest architecture with all the client, server and database residing on single machine. This very architecture is considered as rarely used architecture and is used by database learners in their local machine itself.
For example: If you install local servers like XAMPP or WAMPP or MAMPP etc. in your PC with MySQL and start learning SQL queries from your web browser, it can be considered as 1 – Tier architecture.
Two Tier database architecture is the one in which whole system is divided into presentation layer and data layer where presentation as well as application layer run on the client devices and database reside on the server computers. It is also known as client-server architecture. In this architecture, the database management system resides on a server computer that is more powerful machines capable of providing service to many clients at once. Application Program Interface(API) standards like ODBC(Open Database Connectivity) and JDBC(Java Database Connectivity) are used for interaction between the client and the server. For this purpose, client first sends connection request to server machine and connection is established after server response. As database and end users are located in different sites, this architecture is considered as secured as well.
For example: Contact Management System created using MS- Access can be considered as an example of Two Tier architecture. Also, Applications like Microsoft Word or PowerPoint running on college’s local servers and students using those applications can be considered as 2-Tier.
Three Tier database architecture is the one in which Presentation layer, Business Logic Layer and Data Layer are separated from each other. The client device acts as merely a front end and does not contain any direct database calls. Instead, the client communicates with a tier where all the business logics are implemented called application server. Clients usually interact with application server through a forms interface. Application server on the other hand communicates with a database system to access data. The business logic of the application, which says what actions to carry out under what conditions, is embedded in the application server, instead of being distributed across multiple clients. Three – Tier applications are more appropriate for large applications, and for applications that run on the World Wide Web especially.
For example: Travel destination listing website www.nepaltourismhub.com hosted on internet, E-banking service provided by Sanima Bank etc.
I hope you understand the basic behind DBMS architectures and their use cases.
Thanks for reading! – geeksagar