In MySQL 5.7.2 a new include file “–source include/force_myisam_default.inc“ made its appearance in most of the .test files in the MTR suite. If you were wondering about this read on.

I will explain this change in two blogs. The first will describe why we are doing this and the next will explain how it is being done.

In order to set the context let me delve a bit into history. Starting from MySQL 5.5, the default storage engine for new tables is InnoDB. This change was coupled with a reverse switch in mysql-test-run, which made MyISAM the default storage engine for the server started through MTR(mysql-test-run). As a result default storage engine in the server was innodb, but most tests were run with the old default MyISAM.

Let me explain why such a switch was required. The usual practice in MTR test development was to not specify an engine in create table statement, unless the test is specifically for a …

I have recently moved to HP's Advanced Technology Group which is a new group in HP and as part of that I will be blogging a lot more about the Open Source things I and others in HP work on day to day.  I thought I would kick this off by talking about work that a colleague of mine, Patrick Crews, worked on several months ago.

For those who don't know Patrick, he is a great Devops Engineer and QA.  He will find new automated ways of breaking things that will torture applications (and the Engineers who write them). I don't know if I am proud or ashamed to say he has found many bugs in code that I have written by doing the software equivalent of beating it with a sledgehammer.

Every Devops Engineer worth his salt knows that backups are important, but one thing that is regularly forgotten about is to check whether the backups are good.  A colleague of mine …

Early this year Oracle released  MySQL 5.6 – Best MySQL Release Ever. This release delivered not only quality, but also quantity in terms of number of features. See a comprehensive list here . The blogs below also refer to the massive changes introduced in 5.6
http://www.mysqlperformanceblog.com/2013/01/27/mysql-5-6-improvements-in-the-nutshell/
http://www.flamingspork.com/blog/2013/03/05/mysql-code-size/

It is no mean task to deliver so many features with high quality that too for a feature rich product like MySQL. This was made …

I have been doing quite a lot of benchmarking recently.
I needed to find a safe way of measuring the time spend by the database doing a long task, like catching up on a huge backlog of accumulated replication updates. The problem with measuring this event is that I can record when it starts, but I can't easily detect when it finishes. My initial approach was to monitor the database and count the tables rows to see when the task was done, but I ended up affecting the task performance with my additional queries. So I thought of another method.
Since I had control on what was sent from the master to the slave, I used the following:
The initial time is calculated as the minimum creation time of the databases that I know are created during the exercise. Let's say that I had 5 databases named from db1 to db5:

set @START = (select min(create_time) from information_schema.tables where table_schema like "db%")

…

The MySQL general log is one of my favorite features for a quick debug. I especially like the ability of starting and stopping it on demand, which was introduced in MySQL 5.1.
However, using the general log has its drawbacks.
Today I was debugging a nasty bug that results from two statements that should be applied sequentially, but that were instead concurrent. These kind of problems are hard to cope with, as they are intermittent. Sometimes all goes well, and you get the expected result. And then, sometimes the statements fly on different directions and I stare at the screen, trying to understand where did they stray.
After some try-and-fail, I decided to enable the general log just before the offending statements, and to turn it down immediately after. Guess what? With the general log on, the test never failed. What was an intermittently …

QA-Testing Definitions-Interview Questions: II (F – S): Data Dictionary: A database that contains definitions of all data items defined during analysis. Data Flow Diagram: A modeling notation that represents a functional decomposition of a system. Data Driven Testing: Testing in which the action of a test case is parameterized by externally defined data values, maintained […]

A community member recently noted, that it takes quite a long time to compile MySQL Workbench. So he started wondering about how big the project actually is and asked for the Lines Of Code we have in our MySQL Workbench 5.2 repository.

We did not have this information at hand and therefore Alfredo ran some scripts during the weekend and generated this nice breakdown.

As you can see, we almost have 700k lines of code to maintain. Given that the MySQL Server itself has about 900k lines of code this is a pretty decent number I think, especially for a small team of 7.