By Scot Becker on 10/22/2004

In some DBMS’s, the order in which columns appear in the creation/definition of an index (which spans multiple columns) can have performance impacts. Should you be saddled with such a silly restriction, you might be wondering how to specify the column order within Visio. Read More...

By Scot Becker on 10/22/2004

The Category symbol in an ER Source or Database Model Diagram has a couple of settings that help to describe some semantics of the categorization (a.k.a. subtype, specialization). Read More...

By Scot Becker on 10/20/2004

For any given fact type, there are n! (read: n factorial) readings of that fact type (where n is the number of roles in the fact type). In a unary fact type, there is exactly one reading, in a binary there are two readings, in a ternary there are six readings (3 x 2 x 1), in a quaternary there are 24 readings (4 x 3 x 2 x 1), and so on. Read More...

By Scot Becker on 10/18/2004

Occasionally (and especially when a predicate also has ring and/or frequency constraints), it is convenient to display an internal uniqueness constraint on the bottom of the predicate instead of on the top. Read More...

By Scot Becker on 10/18/2004

The primary supertype setting is enabled if a subtype has two or more parent supertypes (i.e. multiple inheritance). Read More...

By Scot Becker on 10/14/2004

Many object types have similar (usually, descriptive) properties. For example, People, Animals, Products, and so on, all have names. This poses a choice for the ORM Modeler: do you create one "Name" object type or multiple? Read More...

By Scot Becker on 10/13/2004

Join-set comparison (i.e. subset, equality, or exclusion) constraints do not appear on the diagram. Read More...

By Scot Becker on 10/13/2004

If you only indicate the reference mode of an object type involved in a ring fact type in any later position of the predicate, the reference mode is not created. Read More...

By Scot Becker on 10/13/2004

Only the one verbalization is produced no matter what the value of the Personal pronoun property. Read More...

By Scot Becker on 10/13/2004

The right click menu option "Show role player(s)" either does nothing or produces an error message. Read More...

By Scot Becker on 10/12/2004

Although Visio supports the standard cut-copy-paste operations found in most software, the results might not be what you expect because Visio separates the notion of the definition of a model element (e.g. a table, object type, predicate, whatever) from the shape(s) used to display that element. Read More...

By Scot Becker on 10/8/2004

Just a quick entry today to describe a couple of Visio display tweaks. Read More...

By Scot Becker on 10/7/2004

I’ll be adding a new section shortly to catalog bugs related to the database functionality (ORM Source, ER Source, and Database Model Diagrams) in Visio for Enterprise Architects. Read More...

By Scot Becker on 10/7/2004

On the "Ref Mode" tab of the "Database Properties" sheet for an object type, you may have noticed the "Type" drop down list. This list is enabled if the selected object type is an entity type and has a simple (internal) reference mode. Read More...

By Scot Becker on 10/5/2004

The Business Rules window (Database | View | Business Rules) has an interesting feature that I never gave much thought about until today. Read More...