Database Reference
In-Depth Information
We can establish the following three major phases in the half century that database
management systems have been under development:
• Navigational databases
• Relational databases
• NoSQL databases
Let's look at these three system types so that we can then more accurately position
graph databases such as Neo4j—the real subject of this topic.
Navigational databases
The original database management systems were developed by legendary computer
scientists such as Charles Bachman, who gave a lot of thought to the way software
should be built in a world of extremely scarce computing resources. Bachman
invented a very natural (and as we will see later, graphical) way to model data: as
a network of interrelated things. The starting point of such a database design was
generally a
Bachman Diagram
(refer to the following diagram), which immediately
feels like it expresses the model of the data structure in a very graph-like fashion:
Customer 1
Customer 2
Customer
Customer-order
set 2
Customer-order
set type
Order 1
Order 3
Order 4
Customer-order
set 1
Order 5
Order
Order 2
Expanded diagram
(longhand representation)
Bachman diagram
(shorthand representation)
