Understanding Memory

Understanding how SAP Sybase IQ allocates memory can help you get the best performance from your system.

• Server Memory
  SAP Sybase IQ allocates heap memory for buffers, transactions, databases, and servers. Shared memory may also be used, but in much smaller quantities.
• Required Memory
  After you determine how much physical memory the operating system and other applications require, calculate how much of the remaining memory is required by SAP Sybase IQ.
• Cache Memory
  Allocate as much memory as possible to the IQ main and temporary buffer caches for optimal performance. Change the defaults to accommodate loads, queries, and applications.
• Large Memory
  The –iqlm startup parameter specifies the maximum amount of large memory that SAP Sybase IQ can dynamically request from the operating system.
• IQ Page Size
  IQ page and buffer cache size affect memory use and disk I/O throughput for the database.
• Wired Memory
  On HP and Solaris platforms, you can designate a specified amount of memory as wired memory. Wired memory is shared memory that is locked into physical memory. The kernel cannot page this memory out of physical memory.