A week ago we found a workaround for a bug in MySQL Cluster making it impossible to run a management node on MacOS X. Until the bug is fixed, you should use the --nodaemon option for the ndb_mgmd executable. Both MySQL Cluster v6.3 and v7.0 are affected.

Currently, I'm starting the management node like this:

 (
  cd /opt/mysql/mysql ; 
  ./libexec/ndb_mgmd -f /opt/mysql/config.ini \
    --nodaemon 2>/dev/null 1>&2 </dev/null &
 )

Obviously, you'll want to change the paths.

Eventually, the bug will get fixed, but until then you got no excuse to not try MySQL Cluster on Mac!

The GA binaries for MySQL Cluster 7.0.9 have been released – download them from http://dev.mysql.com/downloads/select.php?id=14

A summary of the changes can be found in the MySQL Cluster 7.0.9 Change Log

Last week I spent some time speaking with Kevin Weil, head of analytics at Twitter. Twitter, from a technology perspective, has had a bit of a hard time due to their stability issues in their early days.  Kevin was keen to point out that he feels this was due to the incomparable growth Twitter was experiencing at the time and their constant struggle to keep up.  Kevin was also keen to show that Twitter prides themselves on striving for engineering excellence, the creation & contribution to new technologies and generally assisting in pushing the boundaries forward.  Our conversation naturally centered on analytics at Twitter.

Twitter, like many web 2.0 apps, started life as a MySQL based RBDMS application.  Today, Twitter is still using MySQL for much of their online operational functionality (although this is likely to change in the near future – think …

I really like ZRM for MySQL Community Edition for backups. I find
it very simple to install and configure and it gets the job done. It's default settings suits most installations. The challenges arise once you need to adapt it to more complex organizations. Please note that all the issues described on this article refer to Linux installations.
What If DBAs Have No sudo?This was the 1st challenge that I ever faced. ZRM requires full root access at least during installation and in some cases, it requires some sudo permissions to be able to manage its files as well. Some organizations don't grant these permissions to the DBAs complicating the installation. When I looked into the scripts, I didn't see any reason why they wouldn't run in the user space, other than a few hard coded paths. I posted the question in the Zmanda forums and I got an answer with some …

Ok, this is inspired by another post on the same subject. I would have just commented, but there was a required signup. Ew.


While the method there with juggling grants works fine, I'd like to highlight another way that I think is much simpler: use grep & sed to create a file which contains only the table you want to restore.

mysql> show tables;
+------------------+
| Tables_in_gtowey |
+------------------+
| t1               |
| t2               |
| t3               |
+------------------+
3 rows in set (0.00 sec)

# mysqldump gtowey > dump.sql

Given 3 tables in a mysqldump file, lets restore just t2

# grep -n 'Table structure' dump.sql
19:-- Table structure for table …

I’ve teamed up with O’Reilly once again to do another webcast this coming January.  In it, I’ll provide a step-by-step live tutorial of setting up DRBD with MySQL on a couple of virtual servers.  After the live demo there will be time for Q&A as well, so hope you all can tune in.

Register here:  DRBD and MySQL – An HA Match Made In Heaven

Soooooooo, is the MySQL conference going to fizzle out in 2010? If you have been busy waiting to see what will happen with Oracle/Sun/MySQL then you probably didn’t notice that the call for papers did not go out to the community for 2010 UC. I don’t know about you but the MySQL Conference is something I look forward to every year and enjoy attending. Just being there is great for networking and keeping up on innovation not to mention getting out of the office for the better part of a week!

I was planning on submitting a few talks of my own this year but am wondering if the UC in 2010 will even happen. Sure there are some dates around it, April 12-15, found on http://www.mysqlconf.com/ but no other information.

I know that the Percona conference is …

NorthScale's own Patrick Galbraith has, for many years now, authored and maintained the MySQL, and now Drizzle, UDFs for memcached.  Last week, Patrick took this one step further with the latest release, version 1.1, which now includes support for "check and set" (a.k.a. CAS) operations.  

User Defined Functions are available for a number of different databases.  This allows some kind of stored procedure language or other triggers to execute other code imported into the DB.  In the case of the memcached UDF, this means giving stored procedures the ability to call memcached operations.

The general idea here is pretty simple.  Most applications start with a database, though it's always possible to use web services or flat files.  Regardless of where the data is persisted, to keep the cache always up to date with the System of …

Answering questions asked on the site.

Juan asks:

Regarding this question:

I would like to know what database is the most efficient when performing this type of query and if the solutions proposed are already the most efficient.

I am using MySQL but I would like to know if PostgreSQL, Oracle, Microsoft SQL Server or DB2 are much more efficient.

A nice question, this is a common problem for most developers.

For those too lazy to follow the link, the problem in one sentence:

How do I select the whole records, grouped on grouper and holding a group-wise maximum (or minimum) on other column?

I’ve already covered this in …

Installing Apache2 With PHP5 And MySQL Support On Ubuntu 9.10 (LAMP)

LAMP is short for Linux, Apache, MySQL, PHP. This tutorial shows how you can install an Apache2 webserver on an Ubuntu 9.10 server with PHP5 support (mod_php) and MySQL support.