LRU_FOR_SCAN 
The
database parameter LRU_FOR_SCAN governs where data pages that have been scanned into the data cache are placed in the LRU list.
no (default setting): The datapages scanned into the data cache are placed at the end of the LRU list. This means the datapages will removed from the data cache promptly if new entries are made in the LRU list.
yes: The datapages scanned into the data cache remain in the same place in the LRU list as they were before the scan.