`tfloatdbcol`
	ro	value

`tdbcol`
	ro	datatype
	ro	fieldname
	ro	size
	ro	asvariant
	ro	asboolean
	ro	ascurrency
	ro	aslargeint
	ro	asdatetime
	ro	asfloat
	ro	asinteger
	ro	asstring
	ro	asmsestring
	ro	assql
	ro	asid
	ro	asguiid
	ro	isnull

`tvirtualpersistent`