The Historian reference manual (attached below in PDF format) describes the Historic data logging component of the Polyhedra RTRDB. The manual is aimed at Polyhedra system configurers and application writers. The historian is desgigned to capture time-series data by logging changes to designated tables in the database, to store this information and allow it to be transferred to offline archives (which can be brought online as needed), and the allow the information to be queried to allow the production of, say, trend diagrams. It is also possible to export date from archive files to other database systems, and even to stream time-stamped samples to foreign databases as they are generated. For a general introduction to the capabilities of the historian, see this product note.Note: The Polyhedra Historian is not available in Polyhedra Lite or Polyhedra Flash DBMS.
It is recommended that the reader should be familiar with the Polyhedra Overview and the Polyhedra User's Guide prior to reading this document. It is assumed that the reader has knowledge of relational databases, SQL and object-oriented concepts.