Data Layer

Synchronization

First, note that the data here is quite small and won't usually take a noticeable percentage of the available bandwidth (per month for phones) IF AND ONLY IF we keep the chatter to a minimum. Hence we will base all of our synchronization

1. Each table will have a last updated timestamp.
2. Each registered device will be listed in a table and the last updated timestamp for each device will be listed.
3. Each actual change will be stored as a row on the device and include a timestamp and a CRUD operation object.

Tables

Clearly we must have tables for the following:

• Topics
• Beliefs
• Verses
• Devices
• Licenses

For the first three, the question is:

• Question: How long does the string holding the topic need to be? Decision: 50 --> varchar(50).

• Question: How long does the string holding the belief need to be? Decision: Since beliefs may be quite lengthy, we are using text, which is stored separately etc.

• Decision: Verses are a 3-tuple of integer values. Since both chapters and verses are integers starting at 1, all values will be 1-based. E.g. Genesis 1:1 is identified by (1,1,1).

See the create.sql file in the project for the most recent.