Prime Keys are:
	DATE
	APID
	SOURCE
DB Index Keys are same as Prime Keys
All Keywords for series hmi_ground.hk_dayfile:
	APID      	(short)	Application ID as decimal value
	DATE      	(string)	date,date format yyyy.mm.dd
	SOURCE    	(string)	SOURCE, source of data
Segments for series hmi_ground.hk_dayfile:
	file      	   none	generic	day file