Synopsis

Values:SHARED_POOL_RESERVED_MIN_ALLOC to SHARED_POOL_SIZE / 2

Default:SHARED_POOL_SIZE × .05

Specifies the portion of the shared pool space to be reserved for large contiguous requests for shared pool memory. This parameter, along with the SHARED_POOL_RESERVED_MIN_ALLOC parameter, can be used to avoid performance degradation in the shared pool in situations where pool fragmentation forces Oracle to search for and free chunks of unused pool to satisfy the current request. If the value for SHARED_POOL_RESERVED_SIZE exceeds half of the value for SHARED_POOL_SIZE, an error statement is returned. Ideally, this parameter should be large enough to handle any request scanning for memory on the reserved list without flushing objects from the shared pool. The amount of operating system memory, however, may constrain the size of the shared pool.

In general, SHARED_POOL_RESERVED_SIZE should be set to 10% of SHARED_POOL_SIZE. If the shared pool has been tuned, then for most systems this value will be sufficient. SHARED_POOL_RESERVED_SIZE can accept a plain number or a number followed by “K” or “M,” meaning “multiply by 1,000” and “multiply by 1,000,000,” respectively.