globals contains six comma-separated values that specify how much shared memory to allocate to the database cache for each block size. From left to right, each value is the number of megabytes allocated for:
a – no longer used, always 0
b – no longer used, always 0
c – 8–kilobyte blocks
d – 16–kilobyte blocks
e – 32–kilobyte blocks
f – 64–kilobyte blocks
When all six values are set to 0, as they are by default, the system automatically allocates 25% of total physical memory. On a 64–bit system, there is a limit of 16 TB.
Changing This Parameter
To create a database with a block size other than the default 8-KB blocks, you must enable additional block sizes using the DBSizesAllowed parameter in the [Startup] section.
For more information about allocating memory to the database cache, including using the Management Portal to do so, see Allocating Memory to the Database and Routine Caches in the System Administration Guide.
You can also change globals using the Config.configOpens in a new tab class or by editing the CPF.
The routines parameter.
The DBSizesAllowed parameter in the [Startup] section of this reference.
Estimating Memory RequirementsOpens in a new tab in System Resource Planning and Management.
Allocating Memory to the Routine and Database Caches and Large Block Size Considerations in the System Administration Guide.