Used in the a_create_db structure, to specify the value of db_size_unit.
enum { DBSP_UNIT_NONE, DBSP_UNIT_PAGES, DBSP_UNIT_BYTES, DBSP_UNIT_KILOBYTES, DBSP_UNIT_MEGABYTES, DBSP_UNIT_GIGABYTES, DBSP_UNIT_TERABYTES };