allocate max shared memory

Summary information

Default value

0

Range of values

0,1

Status

Dynamic

Display level

Basic

Required role

System Administrator

allocate max shared memory determines whether Adaptive Server allocates all the memory specified by max memory at start-up or only the amount of memory the configuration parameter requires.

By setting allocate max shared memory to 0, you ensure that Adaptive Server uses only the amount of shared memory required by the current configuration, and allocates only the amount of memory required by the configuration parameters at start-up, which is a smaller value than max memory.

If you set allocate max shared memory to 1, Adaptive Server allocates all the memory specified by max memory at start-up. If allocate max shared memory is 1, and if you increase max memory, Adaptive Server immediately uses additional shared memory segments. This means that Adaptive Server always has the memory required for any memory configuration changes you make and there is no performance degradation while the server readjusts for additional memory. However, if you do not predict memory growth accurately, and max memory is set to a large value, you may waste total physical memory.