Understanding DB2 for LUW Buffer Pool I/O
You will get virtually no argument from anybody that buffer pool management is important to good DB2 and application performance. Large buffer pools are a well known wisdom. There are many ideas on buffer pool management, including the number of buffer pools
Over the years DB2 buffer pools have dramatically increased in size to support ever increasing DB2 workloads. It is common today for DB2 installations to have multiple DB2 subsystems/members, each with several large buffer pools.