MySQL is now over four times the size than it was with MySQL 3.23. This has not come in the shape of plugins.

Have we improved modularity over time? I decided to take LoC count for plugins and storage engines (in the case of Drizzle, memory, myisam and innobase are storage engines and everything else comes under plugin). I’ve excluded NDB from these numbers as it is rather massive and is pretty much still a separate thing.

Continuing on from my previous posts, MySQL code size over releases and MariaDB code size I’ve decided to also look into some other code branches. I’ve used the same methodology as my previous few posts: sloccount for C and C++ code only.

There are also other branches around in pretty widespread use (if only within a single company). I grabbed the Google, Facebook and Twitter patches and examined them too, along with Percona Server 5.1 and 5.5.

As the start of a bit of a delve into the various MySQL branches and patch sets that have been around, let’s start looking at the history of MySQL itself. This is how big MySQL has been over all of the major releases since the beginning (where beginning=3.23). (edit: These numbers were all gathered using sloccount and only counting C++ and C source files.)

Taking the inspiration of Valeriy Kravchuk great series of blog posts “Fun with Bugs” (and not http://funwithbugs.com/ which is about both caring for and eating bugs), and since I recently went and run Coverity against Drizzle, I thought I’d have a small series of posts on bugs that it has found (and I’ve fixed).

An idea that has been pervasive in the Drizzle project (and one that I rather subscribe to) is that there is two types of correct: correct and obviously correct. Being obviously correct is much, much better than merely being correct.

The first category of problems that Coverity …

Coverity is a static analysis tool, which although proprietary itself does offer a free scanning service for free and open source software (which is great by the way, I totally owe people who make that happen a frosty beverage).

Prompted by someone volunteering to get MariaDB into the Coverity Scan, I realized that I hadn’t actually followed through with this for Drizzle. So, I went and submitted Drizzle. As a quick overview, this is the number of problems of each severity both projects got back:

Being clear in licensing is a great benefit to users. I’m quite proud that with Drizzle we got to a really simple situation:

• server is GPLv2
• client libraries are BSD licensed and are fresh implementations

We had the complete okay from Sun to have libdrizzle be BSD licensed and for us to work on that.

 Code-based migrations is a new feature as part of the Connector/Net support for Entity Framework 4.3.1. In this tutorial we'll see how we can use it so we can keep track of the changes done to our database creating a new application using the code first approach.

This walk through is based on the approach of code first and it assumes you have a basic understanding of code first Entity Framework, so please make sure to check this subject before going further with Entity Framework Code Based Migrations. The purpose of this post is to show you how you can upgrade your existing database and use the Code First Migrations to keep track of the changes done in your model and replicate them to your database.

So, what impact does enabling the slow query log have on MySQL?

I decided to run some numbers. I’m using my laptop, as we all know the currently most-deployed database servers have mulitple cores, SSDs and many GB of RAM. For the curious: Intel(R) Core(TM) i7-2620M CPU @ 2.70GHz

The benchmark is going to be:
mysqlslap -u root test -S var/tmp/mysqld.1.sock -q 'select 1;' --number-of-queries=1000000 --concurrency=64 --create-schema=test

Which is pretty much “run a whole bunch of nothing, excluding all the overhead of storage engines, optimizer… and focus on logging”.

My first run was going to be with the slow query log on. I’ll start the server with mysql-test-run.pl as it’s just easy:
eatmydata ./mysql-test-run.pl --start-and-exit --mysqld=--slow-query-log --mysqld=--long-query-time=0

The results? It took 18 seconds.

How long without …

Just for the pure insane fun of it, I accepted the challenge of “what can you do with the text format of the schedule?” for BarCampMel. I’m a database guy, so I wanted to load it into a database (which would be Drizzle), and I wanted it to be easy to keep it up to date (this is an unconference after all).

So… the text file itself isn’t in any standard format, so I’d have to parse it. I’m lazy and didn’t want to leave the comfort of the database. Luckily, inside Drizzle, we have a js plugin that lets you execute arbitrary JavaScript. Parsing solved. I needed to get the program and luckily we have the http_functions plugin that uses libcurl to allow us to perform HTTP GET requests. I also wanted it in a table so I could query it when not online, so I needed to load the data. Luckily, in Drizzle we have the built in EXECUTE functionality, so I could just use the JavaScript to parse the response from the HTTP GET request and …