Relational Database
Consulting & Training

Our focus at OpenLine Consulting is on helping you ensure that your relational database applications can be developed quickly, yet still are maintainable, robust, and secure. In addition to consulting, we provide advanced training (primarily Oracle-specific) in the following areas, which can be customized to suit your needs:

We aso provide a variety of educational materials, including many available under a Creative Commons license


OpenLine Consulting provides training and consulting in the Boston area. The principal of OpenLine Consulting, Dr. Ellis Cohen, teaches introductory and advanced courses in Database Management at Boston University's Metropolitan College for undergraduate and master's degree students. He has developed a number of pioneering notations and methodologies for database application design, including Crow Magnum™, and is currently writing a textbook on the Theory, Practice & Methodology of Relational Database Design and Programming. He has a Ph.D. in Computer Science from Carnegie-Mellon University.


Training Topics

  • Conceptual Modeling, Relational Mapping & Database Re-Engineering: Databases are often designed and documented only at the relational level (using tables and other objects directly suported by the database), which can lead to sub-optimal, hard-to-maintain systems. You'll learn how to become an expert at using Extended ER (entity-relationship) models, which communicate essential design details more clearly, and which facilitate exploration of alternative designs. You will also learn how to evaluate and choose among the myriad ways of mapping ER models to relational or object-relational models (i.e. which objects and tables are used and how they reference one another). Finally, you will learn how to reverse-engineer ER designs from existing databases. ER models will be constructed using both UML and Crow Magnum™, an extension of the industry-standard Crow's Foot model meant for agile collaborative design.

  • Agile Database Application Design: You will learn how to rapidly produce or re-engineer effective maintainable application designs for database-backed applications based on
    • Role-Based Operation Modeling, a simplified form of UML's Use Case Modeling,
    • Business Rule Analysis, a technique for unambiguously documenting business rules as access constraints and integrity constraints (divided into state constraints and transition constraints)
    • Business Rule Mapping, a set of techniques for determining how to best implement business rules, addressing both maintainabiliity and performance.

  • Enforcing Complex Integrity Constraints: Complex integrity constraints can be implemented by rejecting improper operations, or attempting to correct them - using triggers, or using application code with either continuous or intermittent checking. You will learn about the details and tradeoffs of alternate implementations for state and transition constraints, the impact of transactions, and show how to deal with cascading corrections, where correction of one integrity constraint violates another. You will understand the power of using manifest views™ to make the code for managing integrity constraints both maintainable and easily testable. Finally, you will learn how to make changes in the relational design (which tables are used and how they reference one another) to replace complex constraints with ones that are easier to maintain.

  • Implementing Access Control: Many database applications implement access control in the middle-tier. You will learn how to do that effectively, using code that is maintainable and reusable, even when high performance is required. You will also learn how to move code into the data-tier, and use database mechanisms including triggers, privileges, views, roles and security policies to produce applications that are signficantly more secure.