Having dual masters is useful, not just for redundancy/resilience, but also for regular maintenance purposes. Managing it is a bit more tricky, but the MMM can help.

Everybody knows that dealing with hierarchies in a relational database is awkward, and depending on your needs it gets ugly, or downright impossible to do quickly in SQL (lots of queries needed, etc).

What if...
- you could do such operations with simple single queries?
- you could have not only simple trees but also complex ones (multiple parents) ?
- you could have complex graphs for friend-of-a-friend or other structures?

From this presentation you will know how to create a scalable full text search solution with MySQL, how to tune MySQL full text search for maximum performance, how to integrate MySQL with external search solutions and much more.

Gmane is an archive of public mailing lists, accessible via the web and NNTP. It has been running for nearly 8 years, and now carries around 12000 mailing lists. It runs on Linux and is powered entirely by Free/Open Source software..

One of the services Gmane offers is a free-text search of over 70 million email messages, built using Xapian and libgmime, and running on a single server. In this presentation, you'll learn exactly how this works.

Slides: http://survex.com/~olly/how_search.gmane.org_works_lca2010/

Memcached is an open source project that provides an extremely simple extremely fast name/value store, widely used for caching database results and web pages. It takes the load off database servers, and speeds up website responsiveness.

Find out how memcached works, what you can use it for, and how to add support for it in your own sites and projects.

PostgreSQL is being used for mission critical applications in enterprises and FOSS projects. As part of a SAAS (Software As a Service) solution, database uptime is even more critical. However, databases need just as much maintainance as application code, and if the database isn't designed correctly, even more.

With large databases, refactoring the database tends to cause long downtimes while data is moved around or table structure changes wait for lock availability. Some database refactorings need exclusive locks which block reads as well.

Testing database application is hard enough when you have only one server. When you need to test performance and scalability by involving multiple servers, then you need either a lot of patience or a tool that can simplify your task.
Using MySQL Sandbox, you can install single or multiple nodes in one host. Combining that with Gearman, a client/server infrastructure for generic tasks, you can work on distributed servers easily, with little worry about the details.
No matter what language you speak, Gearman can meet your needs in C, PHP, Perl, Ruby, shell scripting, and several more.

There are many GUI applications to deal with databases and with MySQL in particular. But for die hard command line enthusiasts, who grew up with Linux, the shell prompt is still prince.
You would be surprised at the vast amount of operations that you can do from the command line. Running commands on several databases at once, filtering users, getting detailed metadata, transferring data from the operating system to a database and the other way around, creating scripts from database data, creating SQL commands from database data.

In recent years, the no-SQL group of non-relational databases have been picking up a lot of momentum and press. Unfortunately, most users are still picking SQL-relational or non-relational databases impetuously or based on misinformation, rather than analyzing what their application needs.

In this whirlwind presentation, Josh Berkus will go over why you might want a relational database or not, and what kinds or non-relational databases are available and what tasks they do well.

Surrogate Key Abuse is a horrible crime which must be stopped in our lifetimes. Josh Berkus, president of the Society to Stop Surrogate Key Abuse, explains what surrogate key abuse is, why it is so evil, and how we can stop it.