DB2 Express Edition and DB2 Workgroup Server Edition memory limits
If you are installing DB2 Express Edition, the maximum allowed memory
for the instance is 4 GB.
If you are installing DB2 Workgroup Server Edition, the maximum allowed
memory for the instance is 64 GB.
The amount of memory allocated to the instance is determined by the
INSTANCE_MEMORY database manager configuration parameter.
Important notes when upgrading from Versions 9.5 or 9.7:
v If the memory configuration for your Versions 9.5 or 9.7 DB2
database product exceeds the allowed limit, the DB2 database
product might not start after upgrading to the current version.
v The self tuning memory manager will not increase your overall
instance memory limit beyond the license limits.