Products and Services

The Asserted Versioning Framework

The AVF provides:

  • Temporal requirements captured in metadata, thereby eliminating the need to express those requirements in data models.
  • Automatic generation of  bi-temporal databases from conventional ERwin logical data models together with metadata specifications of temporal requirements.


  • A canonical schema for all bi-temporal tables, thereby providing physical and semantic interoperability across all bi-temporal tables in all databases in the enterprise.
  • Standard SQL transactions captured by Instead Of triggers, and automatically translated into physical updates to bi-temporal tables.


  • Automatic enforcement of temporal entity integrity and temporal referential integrity, thereby eliminating the need for temporal logic in application programs.
  • For conventional tables in a database which are converted to bi-temporal tables, dynamic conventional data views over those bi-temporal tables, thereby supporting temporal upward compatibility for all queries written against those original conventional tables.


  • For versioned tables and history tables in a database which are converted to bi-temporal tables, dynamic versioned data and history data views over those bi-temporal tables, thereby supporting temporal upward compatibility for all queries written against those tables, and also enabling "data as-was" as well as "data as-is" queries against those tables.

The AVF is available for licensing from Asserted Versioning, LLC, together with consulting services to assist in planning and installation.


On-Site Seminars

We offer the following one-day seminars at a site and for an audience of your choosing:

  • An Introduction to Temporal Data and its Management.
  • Asserted Versioning for Architects and Modelers.
  • Asserted Versioning for DBAs and Programmers.


The first seminar is split into two half-day sessions. The first session, for managers and executives, discusses the management of temporal data in OLTP databases, in operational data stores, in historical data warehouses, and in the fact and dimension structures of data marts and OLAP cubes. It explains the role of bi-temporal tables in these environments, and describes the business value that they alone can provide – the business value of seamless, real-time access to past, present and prospective states of data about what the things of interest to the enterprise used to be like, are like now and may be like in the future.

The second session, for IT technical personnel, provides an historical overview of various approaches to managing temporal data, and points out the similarities and differences among them both in what they do and in how they work. It presents the concepts of non-temporal, uni-temporal and bi-temporal data, and explains how entity integrity and referential integrity apply to uni-temporal and bi-temporal data. It introduces the Allen relationships, which are a partitioning of all positional relationships between two temporally extended data items, and explains the value of that partitioning as a temporal requirements checklist.

The second seminar introduces the Asserted Versioning paradigm for managing temporal data. It begins with an in-depth analysis of the Asserted Versioning canonical schema for bi-temporal tables, and discusses the roles of surrogate keys, business keys and temporal foreign keys in that canonical schema. It goes on to introduce temporal insert, update and delete transactions, showing both how they are written and what the AVF does to apply them to the database. It concludes by explaining how temporal queries can be understood as conventional queries for which a subspace of two-dimensional time is specified for selecting and/or joining data.

The third seminar begins by explaining how Asserted Versioning modifies indexes to support bi-temporal data, and especially how it uses its proprietary "circa flags" to replace range predicates with match predicates. The remainder of the seminar is organized around two interactive sessions with an Asserted Versioning bi-temporal database. The first session illustrates the use of temporal insert, update and delete transactions, and shows both the before- and after-states of tables updated by those transactions. The second session illustrates non-temporal, uni-temporal and bi-temporal queries issued against the physical tables themselves or against various views defined on those physical tables.


Consulting Services

Besides on-site consulting services, we also offer off-site support for all activities associated with managing temporal data in your organization. This includes white papers on requested topics, reviews of documents produced by your organization, and availability for email exchanges and for telephone and web conferencing.