I'm happy to announce the release of Memcached UDFs version 0.3 (downloadable at http://download.tangent.org/memcached_functions_mysql-0.3.tar.gz). In this version:

• 
  
• memc_stats() added
  
• memc_stat_get_keys() added
  
• buffering behavior option added for better performance
  

This will allow you to query the state of your servers. This makes a great way to possibly add tools to monitor the database and memcached from one source.


mysql> select memc_stats('localhost')\G
*************************** 1. row ***************************
memc_stats('localhost'): Listing 2 Server

Server: 127.0.0.1 …

working with the iodbc driver manager on mac os x has been a frustration on two fronts.

first, the installer api functions provided by iodbc constantly set the configuration mode to ODBC_BOTH_DSN, which means you have to keep resetting it to the correct value after nearly every installer api call. this problem is platform-agnostic — the iodbc code is just plain wrong.

second, when called from the odbc administrator application on mac os x, any failures that the driver reports or passes through from the installer api in registering the driver are ignored, and the application instead uses a generic prompt for dsn configuration.

so even with the first problem fixed, the second problem has led to a lot of tail-chasing until i discovered that the odbc administrator application only obtains enough privileges to write to /Library/ODBC as …

I have finalized the design for Federating Connections and part of the design has been implemented so far with amazing results. Overnight the dependency on replication has been reduced. Feed updates no longer are lagging and query load doubled without the need for new hardware.

Social connections (not mySQL connections) at Flickr in particular are directly responsible for permission levels. This allows members to see into a another members photostream. This global requirement means that every logged in page viewed on Flickr requires a database read if the page is not the members own page. So if the cluster is down, all access to photostreams default to the most restrictive state, i.e. public photos only.

As a result, the service needs to be extremely responsive on reads, since possibly every page view on Flickr could produce a realtime query on the contact cluster.

Next, the data has to be redundant and …

End Software Patents earlier claimed that the US economy suffers an $11 billion hit each year due to needless software patents. It turns out that End Software Patents was wrong.

The number is actually $30.4 billion.

What's $20 billion between friends? The group revised upward its earlier, more conservative estimates based on the following [...

Courtesy of our friends at Oracle cost containment company Miro Consulting, I am giving a webinar tomorrow at 1pm EST (click this link for the time in other timezones please. The subject I’ve chosen is how to apply the best practices around advanced supply management that are extremely successful and mature in the product supply [...]

Hey Texans!

This Sunday (3/9) Sun will be hosting an event at La Zona Rosa in Austin and has invited MySQL'ers and community members. Music will be from the Smithereens and Seven Mary Three. And Zack Urlocker will be in attendance.

We up in Dallas are trying to get a group to head South and hope to see you there.

If you are in the Austin area or can get there, this is a great opportunity to socialize.

Recently, I noticed a post on Planet MySQL expressing distaste for surrogate keys. Ever since reading it the topic has been bugging me so I thought I would finally break out a defense for surrogate keys.

Really, it comes down to the right tool for the right job. Like The Force, they can be used for both good and evil. The fact is that a surrogate key can be wildly useful and efficient if used in the right context. For instance, this blog uses surrogate keys here and there. I'll be honest, in some cases it may help and hinder. For instance, to maintain uniqueness, my BlogPosts table has an auto incremented primary key. To me, this makes sense. Yes, I …

Sometimes, the easy solution is not the best one. I saw this problem happening several times. The query returns duplicates, and the first reaction of the developer is to fix it with DISTINCT.

Let's look at an example. Given the data below:

select * from  people;
+-----------+-------+
| person_id | name  |
+-----------+-------+
|         1 | Joe   |
|         2 | Mary  |
|         3 | Frank |
+-----------+-------+
3 rows in set (0.00 sec)

select * from  projects;
+------------+-------------+-----------+
| project_id | descr       | person_id |
+------------+-------------+-----------+
|          1 | Joe First   |         1 |
|          2 | Joe second  |         1 |
|          3 | Mary First  |         2 |
|          4 | Mary second |         2 |
|          5 | Frank first |         3 |
+------------+-------------+-----------+
5 …

Attention MySQL certification candidates and those of you have earned your certifications: Please let us know if you have a new address or email.

First: This keeps us from sending your certificates to your old address. Tracking down your certification package can be very expensive in time and money.

Second: Our recent purchase by Sun means that our certification data will soon be rolled into Sun's certification database. Please help me out by having your data up to date.

So how do you update your address? You can update your data at Pearson VUE's website or send an email to Certification@MySQL.com

Please take two minutes today to save hours of very hard work in the future!

Note to those of you that have written me with words of appreciation and encouragement as well as suggestions for new pop quizzes: First: Thanks for the kind words! Second: If you’re awaiting an answer, please rest assured that I do read your mail! I get mails relating to the pop quizzes daily, so I’m having to work on this in batch mode. You will get an answer from me in a few days.

Today’s question comes from Bertrand Gorge, who tells me he uses this as a test question during interviews. So if you’re looking to work for him, make sure you’ve understood this!

The following two queries do not return the same result. Why ?

SELECT table1.*
FROM table1 LEFT JOIN table2
ON table2.table1_id = table1.id AND table2.val < 5

SELECT table1.*
FROM table1 LEFT JOIN table2
ON table2.table1_id = table1.id WHERE table2.val …