Seft Tuning Memory Management

Self Tuning Memory Management

(STMM)

1. DB2 Support self tuning memory where no DBA intervention is required for memory tuning . As per the workload memory is tuned on the OS level( i.e borrowed or released from/to OS).
2. There are two modes of working 
1. Tuning DATABASE_MEMORY( i.e DATABASE_MEMORY set to AUTOMATIC)
1. Here only one heap(Memory dump) is required and as per the workload it can grow beyond it max limit by borrowing memory from OS.
2. no Tuning DATABASE_MEMORY( i.e DATABASE_MEMORY set to numeric value)
1. Here two or more Heap(memory dump) are required and as per the workload one heap can grow in size resulting other heap to shrink, thus they cannot grow beyond their max limit.
3. Computed
1. Here no tuning is done. As per the computed values from the configuration files memory is allocated to heaps after the database is started.
3. STMM enables tuning of memory across multiple database and instances within single BOX.