Object Oriented Databases Logical Schema
Logical Schema: Let’s propose a schema to define the structures of the data we want to manage. The schema will be composed of classes and their attributes. The most obvious classes that we’ll need are Message, Person, Address and Attachment. The schema proposed here is just a simple example.
Click here to see our example Message Storage and Analysis System, which examines the practical application of Objectivity/DB 's features, within a message system designed for an internet service provider (ISP) to monitor very large quantities of e-mail and instant messages and detect undesirable advertisements (spam) and viruses.
Requirements:
- The system will receive an average of 10,000 messages per second, but at peak times may receive as many as 50,000 messages per second.
- The average size of a message (with attachments) is 5KB.
- The system must be able to store all incoming messages - none may be lost.
- Each valid message must be made available within 2 minutes.
- Two weeks worth of messages will be kept online.
- All messages (even spam) will be stored in a long-term archive that will be queried.
- If a virus is detected in a message, the system will:
- Start an electronic investigation to attempt to determine the source of the virus.
- Determine how the virus spreads itself and use that infor mation to add to the virus detection capabilities.
- Attachments will be saved in the database so that queries can be performed. Those attachments in a recognized format will be stored as structured data. Those in an unrecognized format will be stored as unstructured binary or text objects.