Chapter 3: Configuring Memory

Determining memory availability for Adaptive Server

The more memory that is available, the more resources Adaptive Server has for internal buffers and caches. Having enough memory available for caches reduces the number of times Adaptive Server must read data or procedure plans from disk.

There is no performance penalty for configuring Adaptive Server to use the maximum amount of memory available on your computer. However, assess the other memory needs on your system first, and then configure the Adaptive Server to use only the remaining memory that is still available. Adaptive Server may not be able to start if it cannot acquire the memory for which it is configured.

To determine the maximum amount of memory available on your system for Adaptive Server:

  1. Determine the total amount of physical memory on your computer system.

  2. Subtract the memory required for the operating system from the total physical memory.

  3. Subtract the memory required for other Adaptive Server-related software (for example, Backup Server) that must run on the same machine.

  4. If the machine is not dedicated to Adaptive Server, subtract the memory requirements for other system uses.

    For example, subtract the memory used by any client applications that run on the Adaptive Server machine. Windowing systems, such as X Windows, require a lot of memory and may interfere with Adaptive Server performance when used on the same machine as Adaptive Server.

The memory that remains after subtracting requirements for the operating system and other applications is the total memory available for Adaptive Server.

The value of the max memory configuration parameter specifies the maximum amount of memory to which Adaptive Server is configurable. See “Configuration parameters that affect memory allocation”.