The most important factors in managing disk I/O for an IQ system are:
Having enough disk space for queries and loads
Using that disk space effectively, so that the fastest I/O is available to support the processing speed of high-powered, multi-CPU systems
The sp_iqstatus stored procedure indicates the percentage of space used in the IQ main and temporary stores. If there is not enough temporary or main dbspace available for a buffer or dbspace allocation request, then the statement making the request rolls back. You can create a timer-based event to monitor space usage to help avoid unexpected rollbacks, which may occur in out of space situations on non-privileged operations. See “Dbspace management example”.
Disk striping is an important means of obtaining maximum I/O performance. Disk striping distributes data randomly across multiple disk drives. You can take advantage of disk striping capabilities in your operating system or disk management software and hardware, as well as Sybase IQ internal striping. Sybase IQ disk striping is enabled by default. To understand these disk management techniques, see “Balancing I/O” in Performance and Tuning Guide.
