If the value is greater than 0, blocks remain in the old sublist until an access occurs at least that many ms after the first access. The default value is 0: A block inserted into the old sublist moves immediately to the new sublist the first time it is accessed, no matter how soon after insertion the access occurs.

Specifies how long in milliseconds (ms) a block inserted into the old sublist must stay there after its first access before it can be moved to the new sublist. The default value is 37 (that is, 3/8 of the pool). Specifies the approximate percentage of the buffer pool used for the old block sublist. InnoDB Plugin now provides two system variables that enable LRU algorithm tuning: These effects can be disadvantageous because they push blocks that are in heavy use by other queries out of the new sublist to the old sublist where they become subject to eviction. Blocks may also be loaded by the read-ahead background thread and then moved to the head of the new sublist by a single access. This occurs even for a one-time scan, where the blocks are not otherwise used by other queries. In the case of a table scan (such as performed for a mysqldump operation), each block read by the scan ends up moving to the head of the new sublist because multiple rows are accessed from each block.

In the default operation of the buffer pool, a block when read in is loaded at the midpoint and then moved immediately to the head of the new sublist as soon as an access occurs. * The InnoDB buffer pool is divided into two sublists: A new sublist containing blocks that are heavily used by queries, and an old sublist containing less-used blocks and from which candidates for eviction are taken.

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