This Natural profile parameter specifies the type of storage for the buffer pool cache of a local Natural buffer pool.

Possible settings	ON	This indicates that virtual storage above the 2 GB line is to be used for the buffer pool cache.
	OFF	This indicates that a data space is to be used for the buffer pool cache.
Default setting	OFF
Dynamic specification	yes	This parameter can only be specified dynamically.
Specification within session	no

Notes:

1. This Natural profile parameter is applicable under z/OS only (not for Com-plete).
2. It corresponds to the C64 subparameter of the BPI profile parameter or NTBPI macro.
3. Internally, the BPC64 specification is converted into the equivalent BPI specification; for example: BPC64=ON is converted into BPI=(TYPE=NAT,SEQ=0,C64=ON).
4. The BPC64 parameter only applies to the primary Natural buffer pool (TYPE=NAT, SEQ=0). In the case of a global buffer pool, it is ignored. If there is a primary buffer pool with SEQ=0 in the Natural parameter module, only the C64 setting of this buffer pool is updated.
5. In multi-user environments (for example, under CICS), the BPC64 profile parameter only affects the very first Natural session which initializes the local buffer pool.
6. For general information on the Natural Buffer Pool, see Natural Buffer Pool in the Operations documentation.