The Yes or No indicator specifying whether the buffer pool is set to use extended storage.
When extended storage is turned on for a database, you configure each buffer pool separately to use or not use the extended storage. If a buffer pool is configured to use extended storage, pages forced out of the buffer pool to make more room are copied to extended storage. When these pages are requested again, they are pulled from extended storage back into the buffer pool. If the buffer pool is set not to use extended storage, pages forced out of the buffer pool are no longer cached anywhere.