SAP Sybase IQ allocates heap memory for buffers, transactions, databases, and servers. Shared memory may also be used, but in much smaller quantities.
At the operating system level, SAP Sybase IQ server memory consists of heap memory. For the most part, you do not need to be concerned with whether memory used by SAP Sybase IQ is heap memory or shared memory. All memory allocation is handled automatically. Make sure that your operating system kernel is correctly configured to use shared memory before you run SAP Sybase IQ
Most operating systems use a large percent of available memory for file system buffering. Understand the buffering policies for your operating system to avoid over-allocating memory.
The total memory used for SAP Sybase IQ main and temporary buffer caches, plus SAP Sybase IQ memory overhead, and memory used for the operating system and other applications, must not exceed the physical memory on your system.