
admin.databaseAddRangeFieldIndex( config as element(configuration), database-id as (Number|String), range-indexes as element(db.rangeFieldIndex)[] ) as element(configuration)
This function adds a range field index to the specified database in the configuration.
http://marklogic.com/xdmp/privileges/admin/database
http://marklogic.com/xdmp/privileges/admin/database/{id}
http://marklogic.com/xdmp/privileges/admin/database/index
http://marklogic.com/xdmp/privileges/admin/database/index/{id}
  
  const admin = require('/MarkLogic/admin.xqy');
  const config = admin.getConfiguration()
  const dbid = xdmp.database("Documents")
  const rangespec = admin.databaseRangeFieldIndex("string",
                "fieldname", "http://marklogic.com/collation/",
		fn.false() )
  admin.databaseAddRangeFieldIndex(config, dbid, rangespec)
   //returns the new configuration element -- use admin.saveConfiguration
   //to save the changes to the configuration or pass the configuration
   //to other Admin API functions to make other changes.