Release 10.1A: OpenEdge Development:
Progress Dynamics Basic Development

Obtaining and assigning site numbers

The first step you should take before starting serious application development is to obtain a unique site number for each copy of your development database. When you get to the point of deploying your application to customer sites, you will also want to be able to assign a unique site number to each distinct deployment site. The reason for this is to assure that the special object ID keys, used by the Repository database (and by application databases designed using the same principle), are unique even between different copies of that database. Now take a moment to examine how the object IDs are constructed and what purpose their uniqueness serves.

In essence, the Progress Dynamics Repository database uses a decimal object ID as the unique key field for every table in the Repository. As discussed in the “Object IDs and Site Numbers” section in Chapter 2, "Database Design Principles in Progress Dynamics," you might want to make use of this same technique in your own application database if you are designing a new database or are in a position to make changes to your existing database schema. The site number becomes part of every object ID key value, such that every object ID value for every Repository or application database anywhere has a value that is guaranteed to be absolutely unique. This makes it possible for you to deploy dynamic application components that are defined strictly as data, without concern that the key values from one database that are used to associate related records can have conflicting values with existing records in the database those objects are deployed to. The same holds for any application data that you might need to deploy from one site to another.