Fig. 1 User privileges stored in MyISAM

The Developer Release for MySQL Cluster 7.2 includes a new feature that allows the system data required for checking user access to be shared amongst all of your MySQL Servers. By default all of the tables holding these credentials are stored in MyISAM and so are local to that MySQL Server.

This can become painful to manage – every time you want to create a new user or change their permissions you need to repeat it on every server, miss one out and the user won’t be able to access that server (or will still be able to access it after you withdraw their privileges).

This is illustrated in Fig.1 – The user “fred” is created on one MySQL Server but when Fred attempts to connect to one of the MySQL Servers they’re blocked. This maybe what you wanted to …

Regular readers of this Blog or attendees at the 2010 O’Reilly MySQL Conference may recall a feature that the MySQL Cluster team were working to speed up JOINs (see Jonas’s slides from that conference here). The good news is that work has continued since then and it is now part of the new MySQL Cluster 7.2 Milestone Development Release. This post will step through where to get hold of the binaries and see the benefits for yourself. The examples I try here result in a 25x speedup just by turning the feature on – I’ve also seen a 50x speedup on other queries!

We’re anxious to get feedback on what benefits you see with your application’s JOINs, please respond to this post.

What’s in a name?

If some of this seems familiar but you don’t remember …