Page sets and buffer pools

When a message is put on to a non-shared queue, the queue manager stores the data on a page set in such a way that it can be retrieved when a subsequent operation gets a message from the same queue. If the message is removed from the queue, space in the page set that holds the data is subsequently freed for reuse. As the number of messages held on a queue increases, so the amount of space used in the page set increases, and as the number of messages on a queue reduces, the space used in the page set reduces.

To reduce the overhead of writing data to and reading data from the page sets, the queue manager buffers the updates into processor storage. The amount of storage used to buffer the page set access is controlled through WebSphere MQ objects called buffer pools.

For more information about page sets and buffer pools, see 'Chapter 3 Storage Management'.