Having invested time and energy into your application, nothing could be more exciting than seeing it gain popularity, and seeing your user base grow. However the success of your application could also turn into your worst nightmare! What if the site cannot cope with the load and collapses under its own weight? The ability to grow (and shrink) according to the needs and the available resources is an essential part of designing applications. In this talk we'll cover the fundamental elements of scalability, including aspects involving people, processes and technology. With sound and proven principles and some advice on how to shape your organisation, set the right processes and design your application, this session is a must-see for developers and technical leads alike.

Despite the NoSQL movement trying to flag traditional databases as a dying breed, the RDBMS keeps evolving and adding new powerful weapons to its arsenal. In this talk we'll explore Common Table Expressions (SQL-99) and how SQL handles recursion, breaking the bi-dimensional barriers and paving the way to more complex data structures like trees and graphs, and how we can replicate features from social networks and recommendation systems. We'll also have a look at window functions (SQL:2003) and the advanced reporting features they make finally possible.

Storing tree structures in a bi-dimensional table has always been problematic. The simplest tree models are usually quite inefficient, while more complex ones aren't necessarily better. In this talk I briefly go through the most used models (adjacency list, materialized path, nested sets) and introduce some more advanced ones belonging to the nested intervals family (Farey algorithm, Continued Fractions, and other encodings). I describe the advantages and pitfalls of each model, some proprietary solutions (e.g. Oracle's CONNECT BY) and one of the SQL Standard's upcoming features, Common Table Expressions.