I’ve been thinking about the query cache since last years user conference. One of the features of the query cache is that it’s completely transparent to client. It achieves this by clearing cache entries for tables as soon as the tables are updated. This makes the cache inefficient for tables that are constantly updating.

While thinking about this also thought about slaves and non critical reads. In a replication setup reads that are sent to slaves expect to get data back that might not be the most current. In this situation it doesn’t make sense to expire the cache for every single update because queries running against the slave already know that they are going to get back slightly old data. I thought, “Why not add a time to live to cache entries instead of clearing them for every update?” So, I did.

I added an option to select called sql_cache_ttl. This option instructs the query cache hold the entry in the cache for …

The value of data stored in LAMP applications is increasing at an exponential pace. Indeed, the LAMP stack fuels an economy of its own - with its own currency, lingo and players. While e-commerce is the clear and present evidence of the LAMP powered economy, the currency for this economy is by no means just monetary. Value is manifested in many factors other than financial gains: personal reputation and legacy, karma points, creativity etc. The LAMP stack fires up innovation by enabling new ideas - you can quickly and cost-effectively prototype a concept which other’s may find bizarre.

User generated content (UGC) is one key currency of the LAMP stack. UGC, even votes (ok, diggs) on other’s UGC store tangible and lasting value. While naming “You”, a proxy for UGC, the Time’s Person of the Year 2006, The Time magazine said: “It’s a story about community and collaboration on a scale never seen before. It’s about the many …

Due to unfortunate circumstances, Zak Greant is unable to attend the MySQL User Conference this year.

Because Zak is a good friend (and I am a glutton for punishment), I agreed yesterday to take on his talk for MySQL beginners titled MySQL Sandalcamp. It should be a good session for those who are completely new to MySQL, covering the basics of what a database is, how to create, populate and query tables.

So if you ever wanted to see what I can put together in two days while traveling, stop by and check it out (unless you already know how to assemble a SELECT query, in which case you will be very bored).

Next up, my Hierarchies talk on …

A quick note for those of you enjoying the MySQL Conference & Expo 2007 in Santa Clara this week. As part of Pythian’s Gold sponsorship of the conference, we’re trying something new. We understand that the tradeshow floor for booth sponsors is a bit out of the way, and in any case, there were no [...]

It was a nice enough flight from Ottawa to Chicago to San Jose, if a little long. Security (or the baggage handlers) completely trashed our boxes of information folders, but I think we managed to salvage some… so if you’re looking for information on Pythian, come see us early. The weather here is just like [...]

Despite of my high load at work I decided to release mmm-1.0-pre2 today. There are some small, but critical fixes added and much more coming next week (or little bit later if mysqlconf will take more time than I think).

After the first alpha release I’ve received lots of emails, some messages in mmm-devel mail list and even some bug reports in Google Code bug tracking. One of the most asked things was documentation. So, I decided to write some posts in this blog (sorry to non-sql-related readers) and them compose some docs for final release using these posts and comments from readers. This post will be first in mmm-series and will describe how to use mmm in simple master+master scheme where one master …

My first tutorial today at MySQL Conference 2007 is Scaling and High Availablilty Architectures by Jeremy Cole and Eric Bergen of Proven Scaling.

Basic Tenets

While not discussed, the premise is to Cache Everything. MemCache is a key component to any scalable system.

Lifetime of a scalable system

Using the analogy from a newborn child Jeremy stepped us through the categories Newborn, Toddler, Teenager, Late teens to 20s, Adult.

In Late teens to 20s, is where most systems die a slow death, he termed “the awkward stage”. This is where scalability is critical, and a meltdown for example can ruin you. Downtime is also just not acceptable for your user community.

When your Adult you need to perfect the …

Marten invited me to join the MySQL staff party yesterday at his own house, where everybody would socialize before the rough conference week. I must confess I enjoyed it really much: very nice place with beautiful views, great people from all around the world, Nordic food prepared by a Swedish chef, an incredible magician playing tricks with cards (he found a card in my ear!). Marten’s family was very charming and the ambience was just great. This is a great start for the week

I am spending today preparing for my session at the MySQL conference on Thursday. I'll be speaking on "MySQL and .NET in the Real World" which will cover my experience creating Approver.com and will also include a run-through of the Visual Studio integration with MySQL.

Last year I created a little command-line tool that generates MySQL data access classes for .NET 2.0. It's the tool that generates the data access layer for Approver.com. I am going to open-source this tool this week, most likely before my talk on Thursday, and I will do a demo of the tool as part of my talk at the conference. This tool is very simple -- it doesn't do as much as, say, SubSonic or NHibernate. But it does automatically generate about 80-90% of the data access code used in Approver.com, and it has a few ease-of-use characteristics that I wanted -- mainly a low learning curve, explicit support for MySQL and .NET 2.0 and no dependencies on external libraries other …

Fortune Cookie at the MySQL Pre-Conference Party.