LRU force skips (-lruskips)

-lruskips n

n

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

Use LRU force skips (-lruskips) to specify the number of times a buffer in the buffer pool is accessed before it is placed on the Most Recently Used (MRU) end of the LRU chain. Specifying the LRU force skip parameter is helpful when high LRU latch wait timeouts are occurring (observable in PROMON or by VST). 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 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 -lruskips to zero disables the feature, and is the default.

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

You can use this parameter to support continuous operation of the database. For more information, see Change database parameters while the database is running.