The PCI memory pool is allocated all at once when the PCI Bridge initializes; it does not grow after that. It is controlled by Adaptive Server and is governed by the same restrictions as other memory pools—for example, a single allocation cannot exceed 1MB. The default size of the PCI memory pool is 32,768 KB.
Use the enable pci configuration parameter to enable the PCI memory pool when you configure the server for Java. See the installation guide for your platform.
The default size of the PCI memory pool size is adequate for most nonclustered installations. To increase the size of the memory pool, reset the pci memory size configuration parameter.
For example, to set pci memory size to 13800 pages (each page is 2KB), enter:
sp_configure "pci memory size", 13800
pci memory size is a dynamic configuration parameter; you do not need to restart Adaptive Server for the change to take effect.
If Adaptive Server does not have sufficient memory available to allocate to the memory pool, this configuration change is ignored and the PCI Bridge does not start.
See the System Administration Guide: Volume 1 for more information about pci memory size.
In a multi-engine environment, multiple Adaptive Server tasks can use the Java VM in parallel. As a result, the Java VM requires more memory in a multi-engine environment than in a single-engine environment. As a result, you may need to increase the size of the PCI memory pool based on the types of applications you are running and the number of users executing Java in parallel.
You can allow Adaptive Server to calculate heap sizes, or you can configure them yourself using sp_jreconfig to set the -Xmx and -Xms arguments of the PCA_JVM_JAVA_OPTIONS directive.
To let Adaptive Server configure heap sizes for you, the calculated heap size must be greater than 4MB and you must not set the -Xmx and -Xms arguments. (Adaptive Server uses the values stored in sybpcidb.)
When Adaptive Server configures heap sizes:
The -Xmx argument of the PCA_JVM_JAVA_OPTIONS directive is set so that the Java heap size is 65% of the PCI memory pool size.
The -Xms argument is set to the same value as -Xmx.
20% of the Java heap size is configured for the young heap generations, also called the Eden space.
