Configuring Memory

All database object pages are sized in terms of the logical page size, which you specify when you build a new master device. All databases—and all objects in every database—use the same logical page size.

• How SAP ASE Allocates Memory
  The size of SAP ASE logical pages (2, 4, 8, or 16K) determines the server’s space allocation.
• Memory Management in SAP ASE
  Memory exists in SAP ASE as total logical or physical memory.
• Determining the Amount of Memory SAP ASE Needs
  The total memory SAP ASE requires to start is the sum of all memory configuration parameters plus the size of the procedure cache plus the size of the buffer cache, where the size of the procedure cache and the size of the buffer cache are expressed in round numbers rather than in percentages.
• Determining the Amount of Memory SAP ASE Can Use
  There are differences between the upper limits of addressable shared memory for SAP ASE versions 12.0 and later versions.
• Configuration Parameters That Affect Memory Allocation
  When setting the SAP ASE memory configuration, use sp_configure to specify each memory requirement with an absolute value. Also specify the size of the procedure and default data caches with absolute values.
• Dynamically Allocating Memory
  SAP ASE dynamically allocates physical memory, which means you can change the memory configuration without restarting the server.
• Configuring Thread Pools
  SAP ASE records individual thread pool information in the configuration file under the Thead Pool heading.
• System Procedures for Configuring Memory
  Use the sp_configure, sp_helpconfig, and sp_monitorconfig system procedures to configure SAP ASE memory.
• Configuration Parameters That Control SAP ASE Memory
  System administrators who are configuring SAP ASE for the first time should check configuration parameters that use large amounts of SAP ASE memory, and those that are commonly changed at a large number of installations.
• Parameters That Use Memory
  SAP ASE includes a number of configuration parameters that use moderate amounts of memory.
• The Statement Cache
  The statement cache saves SQL from cached statements.