I ran into a very interesting issue with a customer recently. The customer was storing JPEGs in MySQL (as BLOBs obviously) and was wanting to setup some additional MySQL slaves. Nothing crazy there. So I did the normal steps of scheduling a mysqldump with the --all-databases and --master-data options. Trouble is, the next day when I start importing the dump, 'mysql' bombed up with "ERROR at line X: Unknown command '\0'". I used 'sed' to pull out the lines around the error and didn't really notice anything out of the ordinary. After a bit of Googling, one suggestion was to do a simultaneous backup and restore (basically a "mysqldump .. | mysql -h ..."). In this case, since I was using an existing slave to do the backups, this was something that was feasible to do. Unfortunately, the result was the same.

It turns out that 'mysqldump' will not always product a dump that is always BLOB friendly. To get around this, the '--hex-blob' option …

Red Hat betas Enterprise Virtualization, partners with HP for SOA. And more.

Follow 451 CAOS Links live @caostheory
“Tracking the open source news wires, so you don’t have to.”

# Red Hat announced that its Enterprise Virtualization portfolio of products is now available for beta testing.

# Red Hat collaborated with HP on SOA.

# David Megginson published mixing GPL and non-GPL: a different perspective. A new take on the MySQL/MariaDB storage engine debate.

# UK Government CIO shed some light on “G-Cloud” plans and how the new open source policy provides an opportunity.

# WAZI: …

As a long-time registrar, we are aware of the importance of keeping up with the internet, as well as trying to be at the forefront of changing technologies as we have done for the past four years. Now it's time to do the same with IPv6!

As a result of this and requests from our customers coupled with the ominous depletion of IPv4 address space, I am pleased to announce that we will be offering IPv6 connectivity for our customers.  Given that IPv6 is the future of the Internet, it is perfectly logical that it is something of particular interest to us.  

This is, of course, not an overnight affair, and will take some time to be able to fully offer the service for all customers, and at the moment we expect to pass through several stages of testing before general deployment.   In any case, we hope to have IPv6 fully available for our customers before the end of the year.

What is the …

If you saw Don MacAskill's keynote (The Smugmug Tale) at the recent MySQL Conference and Expo, you know that he had lots of positive things to say about his experience running MySQL on the Sun Storage 7410 at Smugmug. The 7410 marks the current high end of the Sun Storage 7000 Unified Storage line of network attached storage devices. For the past few months, I have been investigating MySQL database performance on the entry level and mid-range models, to see whether they might provide similar benefits to smaller MySQL sites. I have to admit that I was more than a little …

The PHP UG Berlin has set a new record for the BBQ tour. They tried to collect more attendees than the user group in Munich, but Berlin failed. Some 30 is a little, if not much, less than 34 attendees. As one contest had been lost, the idea of a new contest came up: number of ordered beers. Berlin has won that one easily, if you count glasses. In Munich you get 1l of beer per glass and in Berlin it is more like 0.3l …

It has also been a very close race between Berlin and Munich in terms of PHP "VIPs". Check out the photos. At least five people should look familiar to you, if you have ever been at the PHP Unconference in Hamburg (12-13.09.2009), the PHP room at the …

The PHP UG Berlin has set a new record for the BBQ tour. They tried to collect more attendees than the user group in Munich, but Berlin failed. Some 30 is a little, if not much, less than 34 attendees. As one contest had been lost, the idea of a new contest came up: number of ordered beers. Berlin has won that one easily, if you count glasses. In Munich you get 1l of beer per glass and in Berlin it is more like 0.3l …

It has also been a very close race between Berlin and Munich in terms of PHP "VIPs". Check out the photos. At least five people should look familiar to you, if you have ever been at the PHP Unconference in Hamburg (12-13.09.2009), the PHP room at the …

Howard Chu with Johan Andersson at MySQL User Conference 2009

From MySQL Cluster 7.0, it’s possible to use Cluster as the Data Store for the OpenLDAP Directory Server – this has 2 very signifficant implications:

1. All of the advantages of MySQL Cluster (scalability, high availability and cost) can now be applied to your directory server deployment
2. The same data held in a MySQL Cluster database can now be accessed simultaneously using LDAP in addition to SQL, the native C++ interface and all of the connectors available for MySQL

Howard Chu (Chief Architect of the OpenLDAP project and CTO of Symas) will be presenting a Webinar on Wednesday together with Mat Keep from MySQL. I’ll be helping with the Q&A.

Webinar details…

Wednesday, June 24, 2009

…

mysqlhotcopy is a Perl script that uses LOCK TABLES, FLUSH TABLES, and cp or scp to make a database backup quickly. It is the fastest way to make a backup of the database or single tables, but it can be run only on the same machine where the database directories are located. mysqlhotcopy works only for backing up MyISAM and ARCHIVE tables. It runs on Unix and NetWare.


The options can be viewed by executing the following command:
shell>mysqlhotcopy --help


Backup one/many database at once

shell>mysqlhotcopy [options] db_name1...db_nameN /path/to/backup_directory

Using mysqlhotcopy to backup only those tables within a given database that match a regular expression:

shell>mysqlhotcopy [options] db_name./regex/

The regular expression for the table name can be negated by prefixing it with a tilde (“~”):


…

You would hear a big "NO" if you ask some some one about the command to RENAME the DATABASE.

Sometime ago MySQL tried to include the SQL command(This statement was added in MySQL 5.1.7) to rename the database "RENAME {DATABASE | SCHEMA} db_name TO new_db_name;"

but was found to be dangerous and was removed in MySQL 5.1.23. It was intended to enable upgrading pre-5.1 databases to use the encoding implemented in 5.1 for mapping database names to database directory names . However, use of this statement could result in loss of database contents, which is why it was removed. Do not use RENAME DATABASE in earlier versions in which it is present.

Then is there any workaround for this? yes there couple of ways to do this.. below suggestion are given by some of MySQL experts on online forums which I'm including here

A) use …

I spent far too much time this past week trying to find out why a Drupal was not  assigning authenticated user permissions to users who clicked on the validation link they were emailed. Instead, it would simply remove the temporary unverified user permission.

It's supposed to do the latter, but then also follow it up with the former. It turns out the problem was a Drupal bug that was triggered by my MySQL setup.

My Drupals all use a server that is a master in a set-up with two masters an three slaves. This has some implications for the auto_increment integer data type. In order to avoid clashes when two masters each insert a new record simultaneously, a master gets a specific instruction about which IDs it may assign.

These instructions specify how many numbers to skip - typically the number of masters in a cluster - and an offset to add, …