Innodb improved LRU. Algorithm, essentially split memory linked list into two segments.
Young near the head and Old near the end are divided by segment 5/12. New data can only be in the head of the old segment for a certain period of time, and can be upgraded to young only after being accessed again in the old segment for a certain period of time.
The lRU is essentially split into two lRU segments. The advantage of this is to prevent a performance avalanche caused by a sharp drop in memory hit ratio due to full replacement of memory data during a large table scan.
