The latest from the MySQL community

I can’t say I’ve used the ARCHIVE storage engine before, but at the NY MySQL Meetup last night there was discussion of the improvements to ARCHIVE in 5.1 and the fact that you could not DELETE from archive. A simple test confirmed this indeed throws an error.

DROP TABLE IF EXISTS url_log;
CREATE TABLE url_log(
log_id INT UNSIGNED NOT NULL AUTO_INCREMENT,
log_date TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
user_id INT UNSIGNED NULL,
url VARCHAR(100) NOT NULL,
PRIMARY KEY (log_id))
ENGINE=ARCHIVE;

DELETE FROM url_log;
ERROR 1031 (HY000): Table storage engine for 'url_log' doesn't have this option

However, part of MySQL 5.1 which is RC status, there is partitioning. Thinking that one …

VMWare announced that their 2008 revenue growth outlook would be "modestly below" its earlier stated target of 50% and that CEO and founder Diane Greene would be resigning immediately. That double whammy sent VMWare stock tumbling by more than 25%. VMWare appears to have increased competition, not only from Microsoft's recently released near final Hyper-V technology, but also from open source variants from Red Hat, Citrix, Sun and others based on the Xen hypervisor virtual machine monitor. All of these choices are pretty much free, which will be a tough price for VMWare to match. In an odd twist of... READ MORE

My second webinar (hey it's an officially recognized word now!) on memcached, Memcached for MySQL: Advanced Use Cases, is now available on-demand from MySQL website.

Also see:

• Slides for Memcached for MySQL: Advanced Use Cases
  

After stepping off of the GROUP_CONCAT() solution for calculating quantiles I figured it would be nice to find a better way to calculate the median too.
Solution
I previously wrote on how to calculate the median using GROUP_CONCAT(), but I think that this is a better way:

SELECT     AVG(length) AS median                 -- take the average of left and right median
,          MIN(length) AS left_median            -- 
,          MAX(length) AS right_median           --
,          @l          AS left_median_position   --
,          @r          AS right_median_position  --
FROM (
     SELECT     @n, length                       -- @n is just here to …

In http://www.mysqlperformanceblog.com/2008/07/01/should-we-proclaim-mysql-community-edition-dead/, Peter Zaitsev wonders if MySQL’s community edition is dead.

The title of Peter’s inquiry is somewhat misleading, as the database itself works fine. He clarifies a bit with, “there suppose to be 2 yearly binary releases (which are overdue) and 4 predictable yearly source releases, which we have not seen either.” I thought it was clear that “2 per year” doesn’t mean “one every six months”. It’s been eight months, sure. And I don’t actually believe that MySQL is going to have one source release per month until November, to make up for the lack of source releases. However, it’s certainly possible, if not probable.

The fact remains, however, that if you’re just looking for stable, recent, …

We did it. Designing Scalable Architectures with MySQL Proxy was delivered successfully, with over 150 attendees.
There is a large number of questions that were asked during the session, and you can find them in MySQL Proxy FAQ.
The slides, with the highly entertaining images used by John Loehrer to illustrate his point are also online
Finally, John posted his Connection pooler Lua script in the Forge.
Thanks to John Loehrer for his lively presentation, to Jimmy Guerrero and Rich Taylor for organizing the event, to Jan Kneschke, for answering questions online …

I keep talking about Flexviews, but I figured I'd step back and explain exactly what it does and how it can help you maintain aggregate tables cheaply. Read that again. It really is important. If you have a BI or DW running MySQL then you probably spend a lot of your time creating aggregate tables with cron jobs or some other ETL tool.

These aggregate generating queries might take many hours to run, and running multiple aggregations concurrently likely severely impacts performance. The more data you have the longer the aggregations take to run. If you are attempting to answer real-time business questions this presents a big challenge. Flexviews to the rescue. It gets rid of those cron jobs and custom aggregation scripts and replaces them with an API for creating materialized views (a fancy name for those aggregate tables). It supports two kinds of views: COMPLETE and INCREMENTAL refresh.

A COMPLETE materialized …

For those who don’t know the Obfuscator is for reporting bugs and support requests where the schema,data and queries are not allowed to be disclosed.

At the moment it requires PHP5+ and MySQL5+, the only requirement at the moment is the mysqli extension. It’s being written so that a simple command line interface will be added later as well as a way of interfacing with it directly in PHP. Because of the pluggable style infrastructure the possibilities are left wide open.

Features:

• Multiple Query Obfuscation Multiple queries in a single obfuscation
  procedure, so that tables are obfuscated consistently over a few related
  queries.
• Query Reformating the tokeniser will be able to pretty print queries no
  mater how ugly your query is.
• Pluggable Schema Obfuscation Obfuscation of schema will be …

In addition to having the Malaysia University Days, there’s something brewing in Singapore too.

First up, there is the Singapore MySQL Meetup Group, having a meeting in July, at a new location (Sun Solutions Centre, Central Mall). Confirm your attendance for a meetup at 7pm on Monday, July 14 2008.

And the other reason to be in Singapore, is the Sun Developer Days 2008 Singapore, happening on Tuesday, July 15, 2008. This is an all-day long event, held at the Hilton Hotel - register …