Used with db_size, must be one of DBSP_UNIT_NONE, DBSP_UNIT_PAGES, DBSP_UNIT_BYTES, DBSP_UNIT_KILOBYTES, DBSP_UNIT_MEGABYTES, DBSP_UNIT_GIGABYTES, or DBSP_UNIT_TERABYTES.
When not DBSP_UNIT_NONE, it generates the corresponding keyword (for example, DATABASE SIZE 10 MB is generated when db_size is 10 and db_size_unit is DBSP_UNIT_MEGABYTES). See Database size unit enumeration.