This performance enhancement is primarily useful for people with a
large buffer pool size, typically in the multi-gigabyte range. To
take advantage of this speedup, you must set the new
option, and you might also adjust the
When the InnoDB buffer pool is large, many data requests can be satisfied by retrieving from memory. You might encounter bottlenecks from multiple threads trying to access the buffer pool at once. Starting in InnoDB storage engine 1.1, you can enable multiple buffer pools to minimize this contention. Each page that is stored in or read from the buffer pool is assigned to one of the buffer pools randomly, using a hashing function. Each buffer pool manages its own free lists, flush lists, LRUs, and all other data structures connected to a buffer pool, and is protected by its own buffer pool mutex.
To enable this feature, set the
option to a value from 1 (the default) to 64 (the maximum). This
option only takes effect when you set the
innodb_buffer_pool_size to a size of 1 gigabyte
or more. The total size you specify is divided up among all the
buffer pools. We recommend specifying a combination of
innodb_buffer_pool_size so that each buffer
pool instance is a least 1 gigabyte.
This is the User’s Guide for InnoDB storage engine 1.1 for MySQL 5.5, generated on 2010-04-13 (revision: 19994) .