The MySQL Windows Experience Team is proud to announce the release of MySQL for Excel version 1.1.3, the  latest addition to the MySQL Installer for Windows.

MySQL for Excel 1.1.3 is a maintenance release containing a handful of bug fixes and the following minor features:

• Upon saving a Workbook containing Worksheets in Edit Mode, the user is asked if he wants to exit the Edit Mode on all Worksheets before their parent Workbook is saved so the Worksheets are saved unprotected, otherwise the Worksheets will remain protected and the users will be able to unprotect them later retrieving the passkeys from the application log after closing MySQL for Excel.
• Added background coloring to the column names header row of an Import Data operation to have the same look as the one in an Edit Data operation (i.e. gray-ish background).
• Connection passwords can be …

Devart is glad to announce the release of the new versions of dotConnect ADO.NET data providers, LinqConnect ORM solution, and our ORM designer - Entity Developer. New versions of dotConnect data providers offer you Sync Framework support, support for Oracle 12c, improved PgSqlDump component, load balancing support in dotConnect for MySQL, and other features. Entity Developer and LinqConnect now support Oracle 12c.

Devart is glad to announce the release of the new versions of dotConnect ADO.NET data providers, LinqConnect ORM solution, and our ORM designer - Entity Developer. New versions of dotConnect data providers offer you Sync Framework support, support for Oracle 12c, improved PgSqlDump component, load balancing support in dotConnect for MySQL, and other features. Entity Developer and LinqConnect now support Oracle 12c.

I am developing a concurrent application that uses TokuDB to store its database. Sometimes, one of my SQL statements returns with a ‘lock wait timeout exceeded’ error. How do I identify the cause of this error? First, I need to understand a little bit about how TokuDB transactions use locks. Then, I need to understand how to use the MySQL information schema to look at the current state of the locks.

Transactions and Locks

TokuDB uses key range locks to implement serializable transactions. These locks are acquired as the transaction progresses. The locks are released when the transaction commits or aborts.

TokuDB stores these locks in a data structure called the lock tree. The lock tree stores the set of range locks granted to each transaction. In addition, the lock tree stores the set of locks that are not granted due to a conflict with locks granted to some other transaction.

TokuDB 7.1 provides access to …

Like many others, I’ll be taking the MySQL 5.6 certification exam at the end of this month. As Todd blogged, the quick reference pages are available online for the Developer Exam and the DBA Exam. I’ve long considered myself more of a DBA, so I know the the developer exam that I need to study up on these topics:

…

One day, after taking a job using MySQL, I was writing a query quietly at my desk. It was around quittin’ time, and I was whipping up a new report on the monthly sales figures that the CEO needed for his board meeting in the morning. I, in my ignorance, wrote a nice query with a simple little sum() function. What I did not realize is this caused all my rows to sum up to one row when it really should’ve show several rows. This made my report completely inaccurate. Blindly trusting me as I had blindly trusted MySQL, the CEO presented my report to the board who decided that the company was grossly unprofitable and voted to shut it down. Only when I was waiting in the bread line at my local workhouse did I realize my mistake.

That’s me in the bowler.

Okay, so that’s totally made up. Mostly. I caught the error …

October 16, 2013 By Severalnines

Galera uses a preallocated file with a specific size called gcache, used to store the writesets in circular buffer style. By default, its size is 128MB. In this post, we are going to explore how to leverage gcache to improve the operation of a Galera cluster.

Test Case

We have a four node Galera cluster, using the latest release 23.2.7(r157). We have a table called t1 that is replicated by Galera on all nodes. The cluster nodes have allocated the default 128MB gcache.size, and we’ll try to execute a large writeset to see how gcache responds.

mysql> SHOW VARIABLES LIKE …

I have blogged on using MariaDB Dynamic Columns already, and I hope this was useful and introduction. I have a few more things on this subject though, but one so far little known and used feature is the Client API for Dynamic Columns, see the MariaDB Knowledge Base for details. What this is all about is that Dynamic Columns were originally envisioned as a means of managing the "dynamic columns" used by Cassandra when using the MariaDB Cassandra Storage Engine. But as we realize, this is the server side of things (the Storage Engine) but there is a corresponding client library also, that is part of the MariaDB Client API.

As you have seen if you have read my previous blog on this subject, or whatever is written about MariaDB Dynamic Columns elsewhere, …

Here’s a problem some or most of us have encountered. You have a latin1 table defined like below, and your application is storing utf8 data to the column on a latin1 connection. Obviously, double encoding occurs. Now your development team decided to use utf8 everywhere, but during the process you can only have as little to no downtime while keeping your stored data valid.

CREATE TABLE `t` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `c` text,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
master> SET NAMES latin1;
master> INSERT INTO t (c) VALUES ('¡Celebración!');
master> SELECT id, c, HEX(c) FROM t;
+----+-----------------+--------------------------------+
| id | c               | HEX(c)                         |
+----+-----------------+--------------------------------+
|  3 | ¡Celebración!   | C2A143656C656272616369C3B36E21 |
+----+-----------------+--------------------------------+
1 row in set (0.00 sec)
master> SET …

I’ll be in Hong Kong for the upcoming OpenStack Summit Nov 5-8. I’d be thrilled to talk database things with others present, especially around Trove DBaaS (DataBase as a Service) and high availability MySQL for OpenStack deployments.

I was last in Hong Kong in 2010 when I worked for Rackspace. The closest office to me was in Hong Kong so that’s where I did my HR onboarding training. I remember telling friends on the Sunday night before leaving for Hong Kong that I may be able to make dinner later in the week purely depending on if somebody got back to me on if I was going to Hong Kong that week. I was, and I went. I took some photos while there.

Walking from the hotel where we were staying to the Rackspace office could be done pretty much entirely through buildings without going outside. There were bits of art around too, which is just kind of awesome – I’m …