Everyone using Innodb tables probably got use to the fact Innodb tables perform non locking reads, meaning unless you use some modifiers such as LOCK IN SHARE MODE or FOR UPDATE, SELECT statements will not lock any rows while running.

This is generally correct, however there a notable exception - INSERT INTO table1 SELECT * FROM table2. This statement will perform locking read (shared locks) for table2 table. It also applies to similar tables with where clause and joins. It is important for tables which is being read to be Innodb - even if writes are done in MyISAM table.

So why was this done, being pretty bad for MySQL Performance and concurrency ? The reason is - replication. In MySQL before 5.1 replication is statement based which means statements replied on the master should cause the same effect as on the slave. If Innodb would not locking rows in source table other transaction …

The MySQL GUI tools team has released an updated bundle of our popular graphical tools including:

• MySQL Administrator 1.2
• MySQL Query Browser 1.2
• MySQL Migration Toolkit 1.1
• MySQL Workbench 1.1

The latest Migration Toolkit 1.1 now includes support for migrating from Sybase as well as Oracle, Access, SQL Server and, in fact, any database with a JDBC connector.  The team has also been focusing on improving the quality of all the tools and eliminating some of the bugs that confounded users earlier on.  (With more improvements to follow in the next couple of months.)  Check it out!

• MySQL: Graphical Tools
• MySQL: …

Database administrators hate to upgrade their databases. At MySQL, we like to think that we have been early to recognise this, and we have given more or less unlimited support to even very old releases, on a multitude of platforms. However, this has not been without cost to ourselves.

Many of our users know that the cost of maintaining several releases is high. We have thus been asked to clarify our support lifecycle policy. After long internal discussions, that were not always easy, we are now pleased to say that we have an explicit support lifecycle policy. It addresses the timeframes we will provide updates and continued support for current and older versions of the MySQL server.

Keeping older versions alive for a long time is appreciated by our community and our customers alike. However, we are no longer …

The Term Tagging

The popular feature of 'tagging' content is nothing new. The average netizen should have encountered it by now. Tagging was made popular by sites like del.icio.us and flickr, where users can attach free-form strings, so-called 'tags' to their bookmarks and images. The viewer can then use these tags to navigate through one or more user's contents and locate related content.

Scientific Background

The most-cited work on tagging is this research paper from HP, which starts categorizing tagging as 'folksonomy' (folk taxonomy) in contrast to the conventional term taxonomy. A taxonomy is usually a categorization of content according to a hierarchical and exclusive tree of attributes, while the folksonomy is …

By nat

I spent the week before Where 2.0 driving between Berkeley, San Francisco, Palo Alto, Mountain View, and Sunnyvale. One of the companies I met with was Meebo, an instant messaging startup in Palo Alto. Elaine, one of the three founders, is co-chair of the Javascript track at OSCON this year. Read on to learn how persistence pays off, why they make me feel old, and how their users helped them internationalize the site ...

Who

The company was started by three friends: Sandy Jen, Elaine Wherry, and Seth Sternberg. They're Stanford alumni, but all had jobs and worked on Meebo in their spare time. Meebo's actually the third incarnation of the company: they tried backup software, then p2p file sharing, and finally IM. They'd get to a point where they realized "this just isn't going to work" and moved on to …

Here are some pictures from first UG meeting in Denmark.

In my previous blog entry I described how to install a Pre-configured version of the Pentaho BI Platform. That entry concluded with testing a few out of the box samples to verify that the BI Platform is working correctly.

In this entry I will discuss some Pentaho (PCI) post-installation tasks. All these are also described in the Pentaho Quick start Guide.

Running the PCI as a server

A demo environment with samples is nice, but it's even nicer when you can offer the samples right at the fingertips of your audience. Suppose you want let a business play around with some of the samples: you certainly do not want to force them to crawl behind your demo machine. That would be like going to a restaurant and find out that they've only got one plate to eat from, so that all the customers need to queue …

working on the mysql bugs system filled the transition from me working on falcon to joining the connectors team, where i?ll be focusing on the connectivity for scripting languages.

my initial focus will be on python, ruby, and php. i haven?t figured out exactly what it is that i?ll be doing, but a likely candidate for my first big task will be building out the test suites for these so that they can eventually become part of our build verification process.

In my previous post about enhancing the graphs the MySQL Administrator displays I added a remark that there seems to be a difference between MySQL 4.1 and 5.0.

As it seems this has already been reported as MySQL Bug #10210 and fixed, however only for 5.1. Summarizing the bug report is easy: They implemented Heisenberg (or better: the observer effect). You cannot query the counters for e. g. the number of temporary tables created without modifiying it as you go. In 4.1 all the SHOW STATUS... commands (see the manual page) could be executed without modifying the values displayed, because they …

The telecom industry represents a huge opportunity for disruption; its an entrenched industry with commodity products services and many underserved markets.  Not surprisingly, open source technology is starting to nibble away at the edges of this billion dollar market both for products and services.  Digium, the developers of the open source PBX Asterisk, is one of the hot companies in this space enabling companies to implement VOIP systems at a fraction of the cost of proprietary hardware.  Not only is Asterisk open source, but it's built on an open source LAMP stack using MySQL.

• BusinessWeek: Open Source Takes on Telecom
• OnDisruption: …