The latest from the MySQL community

My name is Ravi Krishnamurthy - I am the Chief Software Architect here at Kickfire. I’ll be blogging about our thoughts on database technologies for data warehousing. More specifically I’ll be talking about current challenges, directions going forward, and the simplifications for wider market deployments and other ideas.

Data Warehouse (DW) queries are known to be more complex, more demanding, and longer running than OLTP queries. Some of the distinctive features of these DW queries that produce these characteristics are:

1) Table scan: Most OLTP queries are point queries updating or inserting a few transactional data. Most DW queries on the other hand are reporting or business intelligence (BI) queries which typically touch large numbers of rows of data, often computed by sequential table scans over the large data sets.

2) Many/complex joins: Multiple tables with many joins in the …

Compared to SQL*Plus (Oracle's cmdline client) which can as I understand produce complete paginated reports, the 'mysql' tool has fairly simple output formatting. I'm not generally fussed about that, as there are perfectly good other tools do make snazzy reports with. Some very cross platform (like web based), output PDF, not a problem. You can even write your own quickly these days.

But the cmdline tool has its use. I always teach my students the basics of it, and insist that some exercises are done using this tool. Familiarity (which involves some practice) helps there. Why? If all else fails, you generally do have mysql available on a machine. It's not hindered by remote ssh logins, or anything else. And, of course, for quickly checking something. And that's where the proficiency helps again. So, normally, you get this type of ASCII table:

mysql> select "Hello, world!" AS foo;
 --------------- 
| foo           | …

Peter Zaitsev wrote an interesting item on front-end performance of a website.

I've always tried to look at the front-end from the user perspective, rather than purely technical. Once you weed out what's not really necessary for the user, and also deal with issues like "how important is it that this number is live", you generally look at a fairly different site already ;-)

Before my time at MySQL, I wrote a little gizmo called Measly Mouse which leads a modest but still active life. When reading on from here, please remember it was designed in 2001 and hasn't really been changed since.

Measly Mouse retrieves a page and deals with redirects, CSS and other …

This fellow is pretty amazing: http://beta.ivancover.com/wiki/index.php/Eee_PC_Internal_Upgrades. To the already tiny Eee PC, he added (internally!):

1. USB hub
   
2. GPS with antenna
   
3. Bluetooth
   
4. Card reader w/ additioal SSD
   
5. Power switch (10 dip) for switching all extra foo on/off
   
6. Wifi upgrade 802.11n
   
7. FM transmitter
   
8. Modem (admittedly there's design space for that)
   
9. Touch screen
   
10. Temperature sensor
    
11. Heatsink
    

That's pretty cool...

A bit of advice to anyone wanting to write an article on MySQL that includes setting up users: familiarize yourself with the concept of Least Privileges. That is, only grant those privileges absolutely necessary to do a job and nothing more. I just finished reading an article on how to set up RSyslog to log to a MySQL database. Halfway through the article is a listing showing the grant statement. I’ll share just the fun part:

grant ALL ON Syslog.* …

My first reaction when I see a “grant all” is to ask: why? Why does an application need every database privilege? Well, I finished the article, then went to the RSyslog web site and spent all of 4 minutes researching why the app needs so much privilege. As it turns out, it doesn’t. Right there in blank and white:

“It is sufficient to …

Tonight, I am attending Startup2Startup Dinner on Dave McClure's invitation (Thanks, Dave!). Chad Hurley, CEO and co-founder of YouTube will be speaking at this invitation only event. I will post more updates on my personal blog or you can follow me on Twitter.

I just got back from 3 days of conferences - 2 days at Velocity and one at Structure '08. The Velocity Conference was billed as the 1st conference devoted exclusively to web performance and operations. And the sessions did live up to this. They had over 700 attendees which is not bad for the first time.

Being a performance person, I chose to mostly attend the performance sessions. What I found was that  the sessions were heavily geared towards the client-side. There were sessions on how to tune your javascript, images, reduce network traffic etc. - all trying to reduce the end-user response time.

Our session was of course on tuning the server-side. There was another one on squid/varnish and mysql sharding - but beyond that, client …

Zachary Fox (from Alert Logic too) wrote a very good tutorial on how to run Selenium RC to execute unit tests in a team environment.

If you have multiple users running unit tests concurrently against the same Selenium RC server, some nasty things may happen. Zach explains how to properly setup multiple Selenium RC servers, so everyone can work on their own server.

I spent Monday and Tuesday this week on Velocity Conference It was
quite interesting event worth attending and it was very good to see
the problems in this are going beyond Apache, PHP, Memcache and MySQL.

A lot of talks on this conference was focusing on what is called
"FrontEnd". The meaning of Frontend is not the frontend web server
commonly used in many architectures but rather optimization on the
client side - how to make a browser to do less requests, make them
parallel, fetch less data and execute client side code faster.

Steve Souders mentioned in his talk for Alexa 10 web sites he examined
typically 80-90% of page response time comes from other things than
fetching HTML of the main page - fetching CSS, JavaScript, Images …