Controlling memory use

The table below lists the startup parameters used to fine-tune memory allocation on the server system.

Table 1. Startup parameters that affect memory allocation
Startup parameter Suggested use
Blocks in Database Buffers (-B) Increasing the buffer size decreases the amount of database record I/O by increasing the number of buffers available in memory. This increases memory usage. Increase the -B parameter to use more memory to reduce I/O. Decrease the -B parameter if memory is limited or if database buffer I/O causes paging.
Maximum Clients per Server (-Ma)1 If some number of remote clients overloads the server or exhausts the file descriptors on a system, set this parameter to limit the number of clients.
Maximum Servers (-Mn)1 If a server becomes overloaded with clients, set this parameter to limit the number of servers. If you significantly increase this parameter, you should also increase the Minimum Clients per Server (-Mi) parameter.
Number of Users (-n) Set this parameter large enough to include both local and remote users.
Pin Shared Memory (-pinshm) Use this parameter to prevent the database engine from swapping shared memory contents to disk.
1 Relevant only to database accessed using client/server.