Date: 2014-10-22
Time: 11:10–12:00
Room: Medici I
Level: Intermediate
With a fast-moving pace of modern web applications development small changes to the database schema and functions happen very often. The ability to track, apply and revert them back is crucial for maintaining relational databases in a predictable state. Not employing a structured way to perform database changes is like walking through the minefield without a map.
Different solutions for applying incremental updates to the database schema and sprocs have been proposed in the past. PostgreSQL is a unique RDBMS in this regard: transactional DDL and namespaces provide the ability to apply schema changes in small clear chunks and maintain well-defined state of the application logic using database functions.
Zalando maintains hundreds of changes to a number of 24x7 production PostgreSQL databases without any downtimes caused by those changes for years. The talk describes the infrastructure we built to achieve this.