Its exciting to see Zimbra being purchased for USD$350 million, by Yahoo!. Exciting because its a great product, exciting because I use it daily, and I guess Satish & team (of over 100 employees) deserve a big pat on the back. The other exciting thing to note is that its got MySQL in its core, and if they’re pushing it out farther and wider now thanks to the Yahoo! purchase, all the better.

There are a few things that are unclear, though, even from their FAQ:

• They mention commitment to Zimbra 5, but I’m still waiting for 4.5.7 :P (My Series 60 phone still …

PDO is a PHP extension providing a data-access abstraction layer that can be used with a variety of databases. This gives you the flexibility of changing the database backend without having to alter your access methods. Even if you use MySQL exclusively, PDO can provide advantages; you can use the same data-access methods regardless of the MySQL version. This does away with the need for using the standard MySQL extension with older versions of MySQL and using the MySQLi extension for later versions. An additional advantage is the ability to use object-oriented code regardless of the version of MySQL.

The phrase "security vulnerability" gives most of us the creeps. We are afraid of them. Looking at them rationally, they share a trait with other bugs: All are a pain, but some are a bigger pain than others. And instead of trying to avoid the evil by not talking about it, let's take a look at MySQL's security vulnerability track record over the years, and explain the rationale behind our actions using actual cases from past years.

The Falcon transactional storage engine uses the concept of user-defined tablespaces that are more in line with what one would find in Oracle (tablespaces) or SQL Server (filegroups). Let?s take a quick look at how tablespaces are used within Falcon and what you can and can?t do with them.

This article shows you how to use a little-known InnoDB feature to find out what is holding the lock for which an InnoDB transaction is waiting. I then show you how to use an undocumented feature to make this even easier with innotop. Background One of the most common complaints I’ve heard from DBAs used to other database servers is “I can’t find out who holds the locks that are blocking all these connections and making them time out.

Community version 1.2.1 of Zmanda Recovery Manager (ZRM) for MySQL, a robust and intelligent solution for backup and recovery of MySQL databases is available for download at Zmanda downloads page.

Changes in this release:

1. Bug fixes
2. Source tar ball (including debian package files)
3. Help from ZRM online sites

For documentation see, ZRM for MySQL users manual. Please use bugzilla to report bugs and feature requests. If you have questions or feedback, please post them in forums.

Quite typical query for reporting applications is to find top X values. If you analyze Web Site logs you would look at most popular web pages or search engine keywords which bring you most of the traffic. If you're looking at ecommerce reporting you may be interested in best selling product or top sales people. This information may often need simple select query, however what if you would like to show percents not just absolute value ?

For illustration purposes I've created a syntetic table filled with some 30mil rows evenly spread in 10.000 groups.

PLAIN TEXT SQL:

1. CREATE TABLE `dt` (
2.   `grp` int(10) UNSIGNED NOT NULL,
3.   `slack` varchar(50) DEFAULT NULL
4. ) ENGINE=MyISAM DEFAULT CHARSET=latin1

And I'm using some silly like query to illustrate some search is required, so count(*) can't be optimized away for MyISAM Tables.

To show …

Its been a while since I last blogged. I’ve shifted through many countries now, since my post on UC-J Day 1. Since then, I’ve updated the set, and there are way more photos, even from Day 2. Day 2 photos are more interesting, because I bothered to take my 70-200/2.8 lens with me (no monopod though, so I bumped up the ISO for stability).

Basically, day 2 went on well, with a little less attendees in comparison to day 1, thanks to the horrendous weather. Most of us took cabs, but some brave souls got an umbrella and walked. Heh. Pictures from many sushi dinners should also make their way online soon. There was a very nice reception later on in the evening, with lots of people winning prizes and so on.

The general consensus from all the …

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 …