A buffer pool is an area within DATABASE_MEMORY that is allocated by the database manager during database activation to cache table and index pages that are read from the disk during the execution of a transaction. Buffer pools are allocated in the memory on the local server where the database is active, and they are referred to as Local Buffer Pools (LBP).
Db2 reads and writes blocks of pages between disk storage devices and buffer pools. All data, except for Large Binary Objects (LOB), is moved from the disk to the buffer pools before work is performed against the data. If compression is active, the page is compressed for storage in the buffer pools. In many cases, data is not decompressed until it is returned to the client.
Db2 can perform many types of I/O reads and writes, and tries to determine the best I/O for all work performed. Any I/O performed while the...