The more I work with MySQL Performance Optimization and Optimization for other applications the better I understand I have to less believe in common sense or common sense of documentation writers and do more benchmarks and performance research. I just recently wrote about rather surprising results with sort performance and today I've discovered even read_buffer_size selection may be less than obvious.

What do we generally hear about read_buffer_size tuning ? If you want fast full table scans for large table you should set this variable to some high value. Sample my.cnf values on large memory sizes recommend 1M settings and MySQL built-in default is 128K. Some people having a lot of memory and few concurrent connections set it as high as 32M in hopes for better performance. Lets see if it is …

By Tim O'Reilly

In comments on Andy Oram's recent Radar post about patents, reader Ian Mulvany of Nature made a point that I thought bears repeating as a new top-level entry. Ian wrote:

There is an interesting complement to the patent system in the domain of assigning credit to ideas, which is the academic peer-review system.

The inventor of the idea in the case of academia is the author. The equivalent to the patent office is the editorial board of the academic journal that the author submits to.

There is an idiosyncratic historical connection between the two systems too. Einstein famously worked as a patent clerk in Bern, Switzerland, before becoming a published academic.

At the time …

Read Partitioning In MySQL, Part 1 before reading this post.

Partition pruning is the most critical performance component about partitioning. Partitioning can ease management of your data (for example the ability to just backup or restore a single partition or the ability to drop a no longer needed partition) but the main reason people add partitions is for performance.

Pruning helps performance by only reading the partitions that need to be read for a query. For example, if you have a table range partitioned by year that has partitions for the years 2000 through 2010. If you write a query selecting data between 2002 and 2005, you don't want to have to scan all 10 partitions.
…

The support for Rails in NetBeans IDE has improved considerably in the past few days. Greg and Ludo have been working on ramping up the jMaki NetBeans module as well. This screencast is an update to #web2 and shows how the development experience for creating a jMaki-enabled Rails application is drastically simplified.

The screencast shows how a jMaki-wrapped Yahoo and …

I talked about this matter already, but now it's time to wrap up.
The Summer of code is over, and the project I have mentored is finished, with a new tool as its outcome, the MySQL test creator.

The student who developed this tool, Charlie Cahoon, did a decent job. All in all, considering that it was his first serious developing experience, he got an excellent result. The maturity stage is still alpha, but he did the breakthrough work to get the development of this tool in the right track.

What do we have in hour hands? A tool that will speed up and make …

The glut of information was dulling awareness, not aiding it --Jerry Mander

The aggregate tables enhance reporting performance1 by reducing the amount of data that needs to be queried for widely used reports. Aggregate awareness at the database or the query tool makes the use of aggregate tables transparent to the user of the data warehouse.

Consider the example star schema for a financial services company as a simple case for aggregations:

I’m looking for 2 PHP Programmer for the company I’m working for. I’ll be hiring a Senior and Intermediate PHP programmer. If you’re in Montreal, QC and intrested in drop a comment I’ll contact you. This is not a webmaster/designer etc job, if you’re a pure PHP programmer I want you! Position: Full Time, Permanent Industry: IT Multimedia/Entertainment Qualifications: PHP, MySQL, [...]

This release is part of the unstable 1.5 branch. Its features will ultimately go into the stable 1.6 branch. You can download it from the innotop-devel package.

The major change is a new Command Summary' mode (switch to this mode with the 'C' key) that's similar to mytop's 'c' mode. It shows you the relative size of variables from SHOW STATUS and SHOW VARIABLES.

As I mentioned in the Post Scriptum of an earlier post, JavaScript is not the only language that you can create CouchDB views with. You can now use PHP, too.

Here is how views work again: You specify a JavaScript function that receives a document parameter (which is a JSON object). You can do whatever to that object and return it again. Or you don’t return anything. When a new document is added to a CouchDB database, it gets passed to the JavaScript function and, depending on its return value, is included into the view that is associated with the function &endash; or not.

function(doc)
{
  if("Value" == doc.field) {
   return doc;
  }
}

This function adds the full document to the view when it has a field called field and when that has the value Value. This is just a refresher on how views work …

I hope I got your attention with the title. The politically correct term should be "how to redirect MySQL traffic on Linux", but you probably wouldn't have noticed.
The scenario is this. You want to switch servers without need for the clients to change connection parameters.
Why would you want to do this? Some reasons:

• You want to test a new server version, which you installed to listen to port 13306, and you want to do it without modifying the applications parameters;
• You ant to use MySQL Proxy on port 4040 to log the traffic for a while without restarting the server, in order to debug an inexplicable problem;

Whatever the reason, you can do it.

Here is how you can proceed on Linux.

Set a iptables rule to redirect port 3306 to port 13306 or to port 4040:

sudo …