While I try to keep things simple, sometimes eliminating options and explanations comes back to haunt me. After posting how to open a Fedora firewall port for a LAMP stack, somebody got trapped by my instructions for installing MySQL on Fedora. They got stuck because they had the following setting in their /etc/my.cnf file:

bind-address=localhost.localdomain

I’d suggested using that bind-address value for a DHCP VMware Fedora installation in Step #7. I was trying to create an example for an isolated testing instance, which is why I set the bind-address to a localhost.localdomain value. They raised the following error when they …

After installing the LAMP stack on Fedora, you need to open port 80 in the Firewall to access the PHP programs on the Fedora instance from external servers. You can open a firewall port by launching the firewall-config application as the root user with the following syntax:

firewall-config

The firewall-config utility opens the following dialog:

Click on the Ports tab, and you’ll see the following:

…

Founded in 2004 to help people find great local businesses, Yelp has some 135 million monthly unique visitors. With those traffic volumes Yelp’s 300+ engineers are constantly working to keep things moving smoothly – and when you move that fast you learn many things.

Fortunately for the global MySQL community, three Yelp DBAs will be sharing what they’ve learned at the annual Percona Live MySQL Conference and Expo this April 13-16 in Santa Clara, California.

Say “hello” to Susanne Lehmann, Jenni Snyder and Josh Snyder! I chatted with them over email about their presentations, on how MySQL is used at Yelp, and about the shortage of women in MySQL.

***

Tom: Jenni, you and Josh will be co-presenting “ …

A student posed the question about why table names are case sensitive. That’s because case sensitive table names are the default installation, as qualified in the MySQL documentation. You can verify that with the following query:

SELECT CASE
         WHEN @@lower_case_table_names = 1 THEN
           'Case insensitive tables'
         ELSE
           'Case sensitive tables.'
         END AS "Table Name Status";

The default value returned on Linux is:

+------------------------+
| Table Name Status      |
+------------------------+
| Case sensitive tables. |
+------------------------+
1 row in set (0.00 sec)

The default value for the lower_case_table_names value on the Windows OS is 1 not …

Somebody ran into the following error message trying to query the innodb_sys_foreign and innodb_sys_foreign_cols tables from the information_schema database:

      ERROR 1227 (42000): Access denied; you need (at least one of) the PROCESS privilege(s) for this operation

It’s easy to fix the error, except you must grant the PROCESS privilege. It’s a global privilege and it should only be granted to super users. You grant the privilege global PROCESS privilege to the student user with the following command:

GRANT PROCESS ON *.* TO student;

Then, you can run this query to resolve foreign keys to their referenced primary key column values:

SELECT   SUBSTRING_INDEX(f.id,'/',-1) AS …

I’ve been setting up a simplified lab environment to let my students learn use in class. This added content will show them how to do reverse engineering with MySQL Workbench.

It’s a complete Fedora image with MySQL and Oracle Database 11g for the course. The uncompressed image is 14GB and the compressed image is 5.3GB. I chose Fedora because it’s the smallest open source image that supports both environments, and Fedora is the closest to Red Hat and Oracle Unbreakable Linux. I’m inclined to make the instance available generally but haven’t figured out the best way to do that.

Here are the new instructions I’m adding and if you have any input leave it as a comment.

You connect as the student user, which puts you in the /home/student directory. Once connected to the Fedora OS, you open a Terminal session by clicking on Activities in the upper right hand corner, and then you …

The early release of Fedora 20 disallowed installation of MySQL Workbench but the current version allows it. Almost like Tom Cruise’s Edge of Tomorrow without the drama. All you need to do is follow my earlier instructions for installing MySQL on Fedora 20. I’d check your kernel to know whether it’s supported. You can check that with this command:

<shell> uname -r

My Fedora is at the following version:

3.14.8-200.fc20.x86_64

Then, you can install MySQL Workbench with yum, like this:

<shell> sudo yum install mysql-workbench

It generates the following log file, and if you have Oracle 11g XE …

I hate it when recruiters reach out to you with a message indicating that they are looking for 'key positions' and when you follow up, the tone changes to "we're just looking for engineers." This happens all the time and the latest company to play this recruitment tactic is LinkedIn. Guys, can't you decide whether you are looking to fill a 'key position' or just an engineering position before reaching out to candidates? I can see that mentioning 'key position' will get a candidate's attention but this is just a low level tactic.

OSSCube’s internationally renowned team of MySQL Experts - Sonali Minocha and Rakesh Kumar, lead a successful workshop on setting up MySQL High Availability for your MySQL Database servers. Scheduled on the second day of the conference, September 20th, the workshop was jam packed with enthusiastic participants.

Sonali, Asia’s first MySQL certified DBA and an internationally renowned MySQL expert, …

While calculating the storage requirements in NDB, extra consideration is needed when calculating storage requirement for NDB tables. For tables using the NDB cluster storage engine, there is the factor of 4 – byte alignment to be taken into account when calculating storage requirements. This means that all NDB data storage is done in multiples of 4 bytes.

For Example, let’s say if a column takes 14 bytes to store. In NDB it requires 16 bytes to store. 2bytes will be padding. Because of this only in NDB TINYINT, SMALLINT, MEDUMINT, and INT all require 4 bytes storage per record due to the alignment factor. This rule is not applied in case of BIT data type.

BIT(X) – in NDB storage engine this column will take X bite of storage space, if a table definition contains 1 or more BIT column (up to 32 BIT columns) then NDB Cluster reserves 4 Bytes (32 bytes) per row for these . If the table definition contains more than 32 BIT …