In the context of a Database Management System (DBMS), a client server refers to an architecture where database client machines connect to and access one or more database server machines.
The fundamental principle behind this architecture is the division of functionality. As described in the reference, the idea is to distinguish the various functions required by the DBMS and elegantly divide them into two distinct classes:
- Server Functions: These are typically the core database operations, such as managing the database files, processing queries, handling transactions, ensuring data integrity, and controlling access. These functions reside on the database server machine(s).
- Client Functions: These are the functions that interact with the user or application. They might include presenting data, formatting requests (like SQL queries), and sending these requests to the server. These functions reside on the client machine(s).
How it Works: A Simple Model
In this model:
- A user interacts with an application running on a client machine.
- The client application formulates requests (e.g., retrieve data, update records) and sends them across a network to the database server.
- The database server processes the request, performs the necessary operations on the database, and sends the results back to the client.
- The client application receives the results and presents them to the user.
This separation allows the server to focus solely on efficient data management, while the clients handle user interface and application logic.
Key Takeaway from the Reference
The core insight provided by the reference is that the client-server model for DBMS architecture is based on a simple and elegant concept: identifying all necessary functionalities and logically splitting them into "server responsibilities" and "client responsibilities." This fundamental division is the defining characteristic of this architecture.
This architecture is widely used because it offers several advantages, although the provided reference focuses primarily on defining the structural and functional separation.
