Question

Ive read some theoretical stuff about Distributed databases and was wondering if anyone of you know some good practical references(links or something) regarding sample DDBMS data models, data fragmentation and replication techniques and so on? It doesn’t have to be very complicated.

Answer 1

I’ll attempt a response, as I’ve many years’ practical experience with (distributed) DBMS architectures… though I can’t identify a text I’d recommend that addresses so broad a field. For an overview of the subject area, I’d start with Wikipedia…

• Distributed databases – an overview of what the term means.
• ACID – an overview of some of the main concerns (beside performance and scalability)
• Two phase commit is a common distributed commit protocol used to ensure transactional consistency between nodes in a distributed architecture. The notion of transaction is key to understanding replication.
• Sharding is a technique to partition data that helps exploit parallelism. Such partitioning of database systems is relevant in the context of data fragmentation.
• Many NOSQL approaches focus on distributed performance through relaxing transactional behaviour, though this is not necessarily a consequence of avoiding SQL.

My personal perspective is that a database is just one possible application of distributed software architectures. The distributed nature of a DBMS is a relatively simple concept – but software architectures to make effective use of distributed databases are substantially more involved. No post on database technology would be complete without recommending the writings of Chris Date, whose prolific work spans most of database technology. Another author to consider is Jeff Ullman.

This is far from a complete answer to your question, but – I hope – it allows you to focus on what specific aspects of distributed database technology are of interest to you.