Each of our software products has a relational database at its core. Relational data bases store data in tables that have a logical connection to each other.
In SportsTrak, there is a Student table and each student has a unique Code.
An Event table (Schedule) gives each event an Event Number.
So when a student is entered into an event, another table (CompList) stores the Student Code with the Event Number.
Three files and their relationships
Each data table contains
rows of data
indices (aka indexes or keys - sort orders that can be used on the data)
Relational integrity refers to the concept that the file ComplIst can connect to a valid Event Number and a valid student.
In many databases, all of these logical tables are stored in a single disc file. However, we store each logical table in its own distinct disc file.
eg, In SportsTrak the student table is student.tps andthe program of events is schedule.tps.
This makes it easy to manage files but does introduce the risk that a user can copy a files between folders and think they are doing the right thing but actually break the data integrity connections.