On first glance, it looks like TEXT and VARCHAR can store the same information. However, there are fundamental differences between the way TEXT fields and VARCHAR fields work, which are important to take into consideration.

Standard
VARCHAR is actually part of the ISO SQL:2003 standard; The TEXT data types, including TINYTEXT, are non-standard.

Storage
TEXT data types are stored as separate objects from the tables and result sets that contain them. This storage is transparent — there is no difference in how a query involving a TEXT field is written versus one involving a VARCHAR field. Since TEXT is not stored as part of a row, retrieval of TEXT fields requires extra [edited 1/22] memory overhead.

Maximum VARCHAR length
The maximum row length of a VARCHAR is restricted by the maximum row length of a table. This is 65,535 bytes …

Last month cloud computing and systems management expert John Willis published his best of Cloud Computing for 2009 list he calls the Cloudies.  I am not an expert on the latest developments in cloud computing so it was nice to get a list of the best (in his expert opinion) cloud computing tools. I was especially interested in the latest open source software and I did a little research on each of these projects to see if they had active development mailing lists, regular releases  and a real community behind …

Following on from the earlier article on running MySQL Cluster on a single Windows host, this one looks at installing and running over multiple Windows machines.

Note that MySQL Cluster is still for development use only on Windows – use LINUX or Solaris for live deployments. For the latest status of which platforms are supported for development and deployment, refer to the Supported Platforms matrix.

Target Deployment

In this post, the MySQL Cluster database will be split over 3 Windows machines: …

ClusterJ Architecture

MySQL have been working on a new way of accessing MySQL Cluster using Java. Designed for Java developers, the MySQL Cluster Connector for Java implements an easy-to-use and high performance native Java interface and OpenJPA plug-in that maps Java classes to tables stored in the high availability, real-time MySQL Cluster database.

There is a series of 2 webinars coming up, as always these are free to attend – you just need to register in advance:

Part 1: Tuesday, February 16, 2010: 10:00 Pacific time

• an overview of the MySQL Cluster Connector for Java
• what these technologies bring to Java developers
• implementation details of the MySQL Cluster Java API and Plug-In for OpenJPA
• configuring the connection to …

I happened upon this old LinuxJournal article about how the University of Zululand in South Africa used MySQL and other Free Software to make do with a 128 kbit (and later 768 kbit) internet connection for their staff and students.

This made me remember the trip I made to another African country, Burkina Faso, 15 years ago:

With the huge amount of work and numerous difficult obstacles facing my work on the MariaDB project, it can be …

Motives and the Features

For the servers running in our new network, I was in need for a highly configurable, but easy-to-use backup solution that can take online backups of VMs and MySQL databases running multiple storage engines.

Since my colleagues are all researchers or programmers but there are no dedicated engineers for managing our system, I decided to write a set of command line scripts to accomplish the task instead of using an existing, highly-configurable but time-taking-to-learn backup solutions, like Amanda.

And what I have come up with now is a backup solution with following characteristics, let me introduce them.

• a central backup server able to take backup of other servers over SSH using public-key authentication
• no need to install backup agents into each server
• LVM snapshot-based online, …

According to different sources from the web the decision about the Oracle - Sun merger has been approved by the European commission soon. So at least in the West it is clear what is going on. Let us see what the East decides... [1], [2].

Oracles arch-enemy Microsoft has already brought its weapons in position against the target with its: "Microsoft offers Oracle-phobes MySQL migration tool" [3], [4]. So far so good. Nothing new, nothing special.

What made me a bit edgy was the following Oracle blog series about their Oracle Warehouse Builder (OWB):

• OWB 11gR2 – MySQL Open Connectivity [5]
• OWB 11gR2 – MySQL Bulk Extract [6]

OWB seems to be a great tool to move data around from different sources, to mix them and to extract some useful results.

It looks like with the new 11gR2 release there "... were significant changes to mapping to support native …

According to different sources from the web the decision about the Oracle - Sun merger has been approved by the European commission soon. So at least in the West it is clear what is going on. Let us see what the East decides... [1], [2].

Oracles arch-enemy Microsoft has already brought its weapons in position against the target with its: "Microsoft offers Oracle-phobes MySQL migration tool" [3], [4]. So far so good. Nothing new, nothing special.

What made me a bit edgy was the following Oracle blog series about their Oracle Warehouse Builder (OWB):

• OWB 11gR2 – MySQL Open Connectivity [5]
• OWB 11gR2 – MySQL Bulk Extract [6]

OWB seems to be a great tool to move data around from different sources, to mix them and to extract some useful results.

It looks like with the new 11gR2 release there "... were significant changes to mapping to support native heterogeneous connectivity …

I’ve posted a new table statistics patch which is the next version of the session table/index statistics patch This version of the patch adds slow query log output. If a query is logged to the slow query log it will have row count statistics added to it.

I’m not sure about the format of the log which is why I’m posting this so early. The first format I tried was:

# Time: 100119 19:24:37
# User@Host: [ebergen] @ localhost []
# Query_time: 10 Lock_time: 0 Rows_sent: 7 Rows_examined: 3
# Rows_read: sbtest.foo:3, sbtest.bar:3,
select * from foo a, bar b where sleep(1) = 0;

Discount educational software

Where there …

Some background is needed. Crosstabs (also called data cubes or pivot tables, have been one of my favorite hacks for long time. In 2001 I wrote an article about a simple …