Database

OpenStack’s compute service, nova, manages all of the virtual machines within a OpenStack cloud.

The pv command is one that I really enjoy using but it’s also one that I often forget about.

If you’re running an operation on a large number of rows within a table that uses the InnoDB storage engine, you might see this error:

This problem has cropped up for me a few times, but I’ve always forgotten to make a post about it.

Users of PHPMyAdmin 3.

Some of you may be wondering “why would you want to use Rails without a database?

Upgrading Plesk from 7.

I finally remembered this book when someone asked me about how to get started with PHP and MySQL development.

Before getting started, it’s important to understand why MySQL uses locks.

It’s tough to find examples of dumps that can’t be properly reimported on other servers.

One of the questions I receive the most is: “What version of Plesk works with MySQL 5?

After a couple of weeks, my MySQL replication series has come to a close.

There’s a few final configuration options that may help the performance of your slave MySQL servers.

If you want to make a DBA nervous, just let them know that they need to upgrade MySQL servers that are replicating in a production environment.

While many people might find replicating over an external network to be an odd concept, it does have some uses.

On some occasions, MySQL replication can break down if an statement comes from the master that makes no sense to the slave.

In a perfect world, slaves will contain the same data as the master at all times.

If you have a master with multiple slaves, you can get some performance and save money on hardware by splitting data horizontally among your servers.

An often overlooked benefit of MySQL replication is the ability to make reliable backups without affecting the integrity of the MySQL data.

Although performance is a much larger benefit of replication, it provides some redundancy for your application as well.

MySQL replication can increase performance by allowing developers to spread queries over two servers.

MySQL replication may sound complicated, but it can be done easily.

After I was asked to create a stored procedure on a MySQL 5.

When you dump table data from MySQL, you may end up pulling a large chunk of data and it may exceed the MySQL client’s max_allowed_packet variable.

If you want to convert a MyISAM table to InnoDB, the process is fairly easy, but you can do something extra to speed things up.

If you’ve run MySQL in a replication environment, or if you’ve enabled binary logging for transactional integrity, you know that the binary logs can grow rather quickly.

If an .

This error will pop up when binary logging is enabled, and someone thought it was a good idea to remove binary logs from the filesystem:

While running into MySQL’s open files limit will manifest itself into various error messages, this is the standard one that you’ll receive during a mysqldump:

By default, views in MySQL 5.

Sometimes MySQL’s process list will fill with unauthenticated login entries that look like this:

Help me out!

I’ve been flooded with requests for MySQLTuner and I’ve answered them this weekend.

An often misused and misunderstood aspect of MySQL is the query cache.

Using the InnoDB engine can be tricky due to the ibdata files’ rather untraditional behavior.

MySQL documentation can be awfully flaky - extremely verbose on issues that don’t require such verbosity, and then extremely terse on issues that need a lot of explanation.

Table corruption in MySQL can often wreak havoc on the auto_increment fields.

In some situations, the system time zone will be different than the one in MySQL, even though MySQL is set to use the system time zone.

If this situation pops up in Plesk, it means that a user has changed their MySQL password outside of Plesk.

If you’re used to SHOW PROCESSLIST; or mysqladmin processlist in MySQL, you might be searching for this same functionality in postgresql.

Installing mysql on FreeBSD from ports is one of the oddest installations I’ve ever completed.

On some operating systems, postgresql is not configured to listen on the network.

If there’s one question I get a lot, it would be “Hey, how can I speed up MySQL?

On some servers, you may notice that MySQL is consuming CPU and memory resources when it’s not processing any queries.

If you get this error, you’ve most likely done a file-based MySQL backup restore, and the InnoDB files are hosed.

If you’ve forgotten the root password for a MySQL server, but you know the system root, you can reset the MySQL root password pretty easily.

MySQL’s default configuration sets the maximum simultaneous connections to 100.

If you work on enough servers, you discover that a lot of people put the security of their MySQL server on the back burner.

As most folks know, by default, MySQL limits the size of a MyISAM table at 4GB.