Iterate through Cassandra table with DataStax Python Driver

In most Cassandra use cases a data table is hardly updated or deleted in prevention of tombstones. Versioned records are used to ensure only insertion is used on the table. The result is that Cassandra table is usually much longer than its cousin in relational database. Like it or not, full table scan is still … Read moreIterate through Cassandra table with DataStax Python Driver

Cassandra data model (as opposed to relational model)

Bad data model design with Cassandra causes chronic pains as application scales. I had to re-read about data model design in “Cassandra – the Definitive Guide” and keep my notes and thoughts in this post. The data modelling in the relational world is indoctrinated to every students out of university. It embraces several things: Entity-Relation: … Read moreCassandra data model (as opposed to relational model)

Relational Database Normalization

If database migration involves a schema redesign, we need to follow certain forms. I have good instinct what these forms are. However, I got some questions are particular normal forms and I realized that I cannot spell them all out clearly, except that I learned it all in university (10+ years ago). I decided to … Read moreRelational Database Normalization

High level steps for database migration

Database migration may involve many different types, such as hardware platform migration, one technology to another (relational to relational, relational to NoSQL), on-premise to cloud, etc. In this posting, I outline some key steps at high level to a successful database migration, assuming the migration involves changing DBMS platform. Assessment and discovery – this is … Read moreHigh level steps for database migration

Cassandra Architecture Summary

Disclaimer: many contents here are from Cassandra The Definitive Guide Gossip and Failure Detection Cassandra uses a gossip protocol that allows each node to keep track of state information about the other nodes in the cluster. The gossiper runs every second on a timer. Gossip protocols assumes a faulty network, are commonly commonly employed in … Read moreCassandra Architecture Summary