About the Historian Database Tables

The Historian database tables contain read-only data from the Historian archive. This chapter describes the columns contained in the Historian OLE DB Provider tables:

You cannot perform writes or updates to data in these tables. Almost all columns in Historian OLE DB Provider tables support comparison operators except for the following:

  • SamplingMode
  • Direction
  • NumberOfSamples
  • IntervalMilliseconds
  • CalculationMode
  • FilterTag
  • FilterMode
  • FilterComparisonMode
  • FilterValue
  • FilterExpression
  • TimeZone
  • DaylightSavingTime
  • RowCount

These columns only support the = comparison operator.

Nulls are not supported in any column. A blank space is returned when there is no value supplied by the Historian server, instead of a Null field.