LRU_FOR_SCAN 
The special database parameter LRU_FOR_SCAN governs where data pages that have been scanned into the data cache are placed in the LRU (last recently used) list.
· no(default setting): The data pages scanned into the data cache are placed at the end of the LRU list. This means the data pages will removed from the data cache promptly if other pages are read into the data cache, and new entries are made in the LRU list.
· yes: The data pages read into the data cache are handled according to the LRU algorithm, which means that they are not removed immediately from the data cache when new pages are read.