The database size mainly depends on the size of the data area, which is the set of all data volumes.
Use one of the following database tools: Database Studio or Database Manager CLI
Manually Adding or Removing Data Volumes
More information:
Database Studio, Adding or Deleting Data Volumes
Database Administration in CCMS, Data Area
Automatically Adjusting the Size of the Data Area
More information:
Database Studio, Activating or Deactivating the Dynamic Adjustment of the Data Area
Database Manager CLI, auto_extend, auto_shrink