LRU alternate buffer pool force skips (-lru2skips)

-lru2skips n

n

The number of times to access a buffer in the Alternate Buffer Pool before moving it to the end of the LRU2 chain.

Use LRU alternate buffer pool force skips (-lru2skips) to specify the number of times a buffer in the alternate buffer pool is accessed before it is placed on the Most Recently Used (MRU) end of the LRU chain. Specifying the LRU alternate buffer pool skip parameter is helpful when high LRU latch wait timeouts are occurring (observable in PROMON or by VST) in the alternate buffer pool. Accessing a buffer a specified number of times eliminates the need to acquire the LRU latch each time a buffer is accessed. When the LRU alternate buffer pool skip value is tuned to your environment, contention on the LRU latch decreases, improving concurrency and performance, and there is no increase in the number of page misses in the buffer pool. If increasing the LRU skip value causes increased buffer pool misses, then the value should be tuned down or turned off altogether. Setting -lru2skips to zero disables the feature, and is the default.

To change this parameter while the database is running, use PROMON or the _DbParams VST.