The latest from the MySQL community

In my post on estimating query completion time, I wrote about how I measured the performance on a join between a few tables in a typical star schema data warehousing scenario.

In short, a query that could take several days to run with one join order takes an hour with another, and the optimizer chose the poorer of the two join orders. Why is one join order so much slower than the other, and why did the optimizer not choose the faster one? That's what this post is about.

Let's start with the MySQL query optimizer. The optimizer tries to choose the best join order based on its cost metric; it tries to estimate the cost for a query, then choose the query plan that has the lowest cost. The unit of cost for the MySQL query optimizer is a single random 4k data page read. In general, it's a pretty …

I have already blogged about this keynote at http://www.pythian.com/blogs/948/liveblogging-who-is-the-dick-on-my-site.

If you are interested in actually seeing the video, the 286 Mb .wmv file can be downloaded at http://technocation.org/videos/original/mysqlconf2008/2008_04_17_panelDick.wmv and played through your browser by clicking the “play” link at http://tinyurl.com/55c5ps. This is not to be missed!

I have already blogged about this keynote at http://www.pythian.com/blogs/948/liveblogging-who-is-the-dick-on-my-site.

If you are interested in actually seeing the video, the 286 Mb .wmv file can be downloaded at http://technocation.org/videos/original/mysqlconf2008/2008_04_17_panelDick.wmv and played through your browser by clicking the "play" link here. This is not to be missed!

Discussion on community builds, patches, adding features, etc using GPL version of MySQL source code. It's also a public group, and if you're interested in hacking MySQL source code, please join.


oursql-sources

It's been mentioned before, but I'll mention it again. There's been talk of a community conference, not to compete with but augmenting the Sun/MySQL one. We're here to discuss such an event, its potential, dates/location, and get it going! It's a public group, please blog & tell others about it! Sheeri suggested OurSQL, like her podcast. Created and managed by Arjen Lentz

oursql-conferenceMySQL DBA & Programming Blog by Mark Schoonover

Discussion on community builds, patches, adding features, etc using GPL version of MySQL source code. It's also a public group, and if you're interested in hacking MySQL source code, please join.


oursql-sources

It's been mentioned before, but I'll mention it again. There's been talk of a community conference, not to compete with but augmenting the Sun/MySQL one. We're here to discuss such an event, its potential, dates/location, and get it going! It's a public group, please blog & tell others about it! Sheeri suggested OurSQL, like her podcast. Created and managed by Arjen Lentz

oursql-conferenceMySQL DBA & Programming Blog by Mark Schoonover

The weekly run-down of MFotD

(See this post for background information on MySQL Function of the Day)

Week Seven:

• Monday, April 21st, 2008: ROUND()
• Tuesday, April 22nd, 2008: TRUNCATE
• Wednesday, April 23rd, 2008: LOG()

(more…)

besides a community ?

Some people think that apart from a community and users you also need an infrastructure to support these users.

Murray ignited the discussion by pointing us to the fact that PostgreSQL doesn't have a bugzilla to report an track issues.

Different projects have different approaches. Both the kernel, Drupal and MySQL have build their own infrastructure. Others choose Sourceforge for their projects.

What's your approach ?

Florian is replying to James on the subject of using DRBD for MySQL HA. A discussion started earlier by Eric Florian is refuting most of the arguments that James has against using MySQL and DRBD together.

I`m also saying NO to MySQL and DRBD in most of the cases.. but not for any of the reasons James mentions.

I must say upfront I love DRBD and I have been using it in production for a long time but not for MySQL HA.

The problem with using MySQL on DRBD is the same problem you have when killing the power on a standalone MySQL machine and rebooting that machine.
DRBD saves you the time of powering up your machine and OS. But MySQL …

I was at the O'Reilly Web 2.0 Expo in San Francisco last week, I thought about what I saw over the weekend. There seemed to be two Big Ideas at this conference:

1. That applications will move into the cloud/grid/utility, with everybody from Sun, Amazon, and Google to traditional hosting ISPs offering new clout/grid/utility computing solutions.

2. The big players are now moving away from software and software as a service to Platform as a Service. Yahoo, Google, Salesforce.com, Amazon, etc. are all opening up their APIs to turn them into platforms where you can come in and build your own applications on top of them.

What I Think (In Case You Cared...)

I don't think we'll ever move back to the days of dumb terminals and centralized applications run by service bureaus. Nevertheless, I was very excited by what I saw, because by making available both the hardware infrastructure and their …

It is perhaps fitting that the last word on the recent MySQL licensing row should belong to Sun’s CEO, Jonathan Schwartz. In a twitter Q&A with Web 2.0 Expo attendees, courtesy of Tim O’Reilly, he states that:

“we have no plans whatever of ‘hiding the ball,’ of keeping any technology from the community. Everything Sun delivers will be freely available, via a free and open license (either GPL, LGPL or Mozilla/CDDL), to the community.

Everything.

No exception.”

Which would appear to be pretty conclusive, despite his additional claim that “leaders at Sun have the autonomy to do what they think is right to maximize their business value - so long as they remember their responsibility to the corporation and all of its communities (from shareholders to developers). Not just …