The first column defined for each table contains the sample timestamp field. It is always named Timestamp and has the datatime datatype.
The names of the remaining table columns are derived from the data items that they represent. Each column name is dataitemname_stattype where:
dataitemname is a compressed form of the data item’s name.
stattype is an abbreviated form of the data item’s statistic type.
Each column is assigned a datatype that is appropriate for the type of information that the data item represents. All columns except the sample timestamp column can contain null values.