Size of shared memory for global cache.
Six comma-separated values specify how many megabytes of shared memory to allocate for different sizes of global cache. From left to right, each value is the number of megabytes for global caches organized into:
So, for example, the following setting:
Allocates 16 megabytes of buffers for 8kilobyte database blocks.
Allocate 8mb of 4kb blocks and 32 mb of 8kb blocks:
Allocate 32 mb of 8kb blocks. If a need for a 4kb block exists, then the system uses an 8kb block to store it since no 4kb blocks are configured:
Let the system allocate memory itself by setting all parameters to 0.
Range of Values
If all the values are 0, space is automatically allocated based on an estimate of the machine capability and shared memory resources. On a 64bit system, there is a limit of 16 TB.