Virtual Address Space

To avoid excessive system page faulting, the virtual address space should be less than the physical memory of the machine.

The virtual address space of a process is the total size of the process. The working set of a process is the amount of physical memory currently allocated to the process. To avoid excessive system page faulting, the virtual address space for the Sybase IQ process(es) should be less than the physical memory of the machine.

Due to the virtual memory usage pattern within the Sybase IQ server, virtual memory fragmentation could cause excessive process growth on Windows platforms. To reduce the likelihood of this situation, Sybase IQ supports the use of Microsoft's low-fragmentation heap (LFH) on Windows XP and Windows Server 2003.

• Monitoring Virtual Address Space and Memory Usage
  Change the options in Task Manager to monitor virtual address space and memory usage.
• Monitoring Page Faults
  Use Windows Performance Monitor to track the number of hard page faults, which can indicate that the physical memory of the machine has been overallocated.