TransGlobal Transport and Shipping (TGTS) coordinates the movement of goods around the globe for businesses of all sizes. Customers of TGTS contact the shipper and provide detailed information about packages and cargo that need to be shipped. Simple orders can be a single package shipped across the country, and more complicated orders can entail hundreds of parcels or shipping containers that are transported internationally. To help their customers track their shipments, TGTS is developing a mobile app called TGTS Tracker.

TGTS Tracker will run on the most popular mobile device platforms. To allow customers to monitor their shipments from any of their mobile devices, application designers have decided to keep configuration information about each customer in a centralized database. This configuration information includes

• Customer name and account number

• Default currency for pricing information

• Shipment attributes to appear in the summary dashboard

• Alerts and notification preferences

In addition to configuration information, designers want the app to quickly display summary information in a dashboard. Slower response times are acceptable when customers need to look up more detailed information about shipments. The database supporting TGTS Tracker should support up to 10,000 simultaneous users, with reads making up 90% of all I/O operations.

The design team evaluated relational databases and key-value databases. Relational databases are well suited to manage complex relations between multiple tables, but the need for scalability and fast read operations convinced them that a key-value database was the better choice for TGTS Tracker.

The range of data that is required by the mobile app is fairly limited so the designers felt confident that a single namespace would be sufficient. They chose TrackerNS as the name of the app’s namespace.

Each customer has an account number, so this was selected as a unique identifier for each customer.

The designers then moved on to decide on the structure of values. After reviewing preliminary designs of the user interface, they determined that name and account number appear frequently together, so it made sense to keep them together in a single list of values. The default currency is also frequently required, so it is included in the list of values along with the customer name and account number. Because this app is designed to track the status of shipments, there is little need for administrative information, such as billing address, so it is not stored in the key-value database.

The app designers decided to use the following naming convention for keys: entity type: account number.

Decide the entity types

Attributes about the entity

Give a sample of key-value pairs.