Background concepts

This section provides an overview of how Adaptive Server processes client requests. It also reviews threading and other related fundamentals.

Like an operating - system, a relational database must be able to respond to the requests of many concurrent users. Adaptive Server is based on a multithreaded, single-process architecture that allows it to manage thousands of client connections and multiple concurrent client requests without overburdening the operating - system.

In a system with multiple CPUs, you can enhance performance by configuring Adaptive Server to run using multiple Adaptive Server engines. Each engine is a single operating - system process that yields high performance when you configure one engine per CPU.

All engines are peers that communicate through shared memory as they act upon common user databases and internal structures such as data caches and lock chains. Adaptive Server engines service client requests. They perform all database functions, including searching data caches, issuing disk I/O read and write requests, requesting and releasing locks, updating, and logging.

Adaptive Server manages the way in which CPU resources are shared between the engines that process client requests. It also manages system services (such as database locking, disk I/O, and network I/O) that impact processing resources.