Community journal

The latest from the MySQL community

Ideas, releases, practical guides, and perspectives from the people building with MySQL.

Follow the feed
Showing entries 35991 to 36000 of 45505 « Previous | Next »
The most misunderstood character in MySQL's SQL-Dialect

Many MySQL users like to use the MySQL monitor. The MySQL monitor is the executable bin/mysql (or if you are on MS Windows, bin\mysql.exe) and is perhaps better known as the MySQL command-line tool or MySQL command-line client.The MySQL monitorBasically, the MySQL monitor is a standard, text-based terminal that connects to a running MySQL Server when it is started. Once the connection is established, the user can enter text via the computer keyboard, which is at some point sent to the server. The server attempts to interpret the received text as SQL, which is then executed, sending the result back to the MySQL monitor. The MySQL monitor then prints the received results on the screen:


mysql> SELECT COUNT(*) FROM world.City;
+----------+
| …
[Read more]
Community Team interview with Mårten Mickos about the Sun Acquisition

We have just published an interview with our CEO Mårten Mickos on our Developer Zone, where he answers a number of questions from the Community Team about Sun's plans to acquire MySQL AB and what this means for the MySQL User Community and the direction of the product (thanks to Colin for compiling and editing the text). I hope that the comments help to calm the concerns of some people about the future of MySQL with regards to Open Source, support of platforms or language bindings:

CT: Is MySQL fully committed to free and open source software, and the GPL?
Mårten: Yes.
CT: What does the Sun acquisition mean for Linux support? What about Windows, Mac OS/X and other platforms?
Mårten: One of the reasons …

[Read more]
TOTD #24: Getting Started with Rails 2.0.x in JRuby 1.0.3 and JRuby 1.1RC1


This TOTD (Tip Of The Day) shows how to install Rails 2.0.x in JRuby 1.0.3 and JRuby 1.1 RC1. Then it describes how a simple Rails application can be created and deployed using WEBrick.

First, lets deal with installing Rails 2.0.x in JRuby 1.0.3 and JRuby 1.1 RC1.

Step 1: How to install Rails 2.0.x in JRuby 1.0.3 ?

  • Download and Unzip JRuby 1.0.3. This creates "jruby-1.0.3" directory.
  • Install Rails by giving the following command in the newly created directory:

    bin/jruby -S gem install rails --include-dependencies --no-ri --no-rdoc
    Bulk updating Gem source index for: http://gems.rubyforge.org
    Successfully installed rails-2.0.2
    Successfully installed activesupport-2.0.2
    Successfully installed activerecord-2.0.2
    …
[Read more]
SSD + MyISAM Thread Scalability

A

Defensive Patents, Other Fairy Tales

"Defensive patents" make as much sense as leaving a loaded gun around the house. Like a home robbery, it is more likely it will be used against the home owner then the intruder.

If you have an idea, publish it to establish prior art. Patent trolls come from patent houses that produce no products. This means that they
cannot be counter sued. The fallacy with defensive patents is assuming you will ever use it as a weapon.

What should you really fear? The company you work for changes direction or goes under. It then sells the patent, and the patent ends up in the hands of a patent house.

Trust the people you know running your company?

If you do not, you should be finding a different employer.

But what about the next guy?

You can never know.

The solution is to establish prior art. Defensive patenting just continues the cycle of software …

[Read more]
Sun's Schwartz Cites MySQL's Growth Rate as Incentive
FastSessions Rails Plugin Released

How often do we think about our http sessions implementation? I mean, do you know, how your currently used sessions-related code will behave when sessions number in your database will grow up to millions (or, even, hundreds of millions) of records? This is one of the things we do not think about. But if you’ll think about it, you’ll notice, that 99% of your session-related operations are read-only and 99% of your sessions writes are not needed. Almost all your sessions table records have the same information: session_id and serialized empty session in the data field.

Looking at this sessions-related situation we have created really simple (and, at the same time, really useful for large Rails projects) plugin, which replaces ActiveRecord-based session store and makes sessions much more effective. Below you can find some information about implementation details and decisions we’ve made in this plugin, but if you just want to try it, then …

[Read more]
A Q&A Session with Mårten Mickos, CEO of MySQL AB, about the Sun Acquisition

We got a chance to speak with Mårten Mickos, CEO of MySQL AB, about Sun's planned acquisition of MySQL, and we asked him some questions, that the community at large, might have.

Implementing a Replication precacher

I've completed a beta implementation of my take on the replication pre-cache tool... Sorry nothing to download yet, I have to get it through an internal committee at Yahoo before I can release it (and you can imagine things are kind of crazy here).  I wrote it myself because:

  1. I had it mostly done before I found out there were other versions out there
  2. I have to maintain it inside of Yahoo anyway
  3. I wanted to learn Ruby :)


It's just over 250 lines of Ruby, my new favorite language and fairly compact.  It doesn't use the Ruby Mysql library, rather just IO.popen calls to the mysql command line client.  I did this for two reasons: 

  1. I haven't figured out the "right" way to deploy ruby gems at Yahoo yet (it's complicated).

read …

[Read more]
Answers to Questions from Today's Performance Coding Webinar

Thanks to everyone who attended the performance coding webinar today. I think there were about 250 people online, which is a great turnout! Sorry for dropping off about fifteen minutes into the webinar — that'll teach me to use Skype for presenting!

There were a bunch of questions from attendees and I have tried to quote them and answer to the best of my knowledge below. They are in no particular order, and where possible, I refer to the slide where I think the question referred to. Happy tuning and coding!

Miscellaneous Questions Will MySQL Support Functional Indexes Soon?

This comes up every time! Not sure why...perhaps there's lots of Oracle and DB2 users also using MySQL and wanting to migrate to MySQL without changing schemas. In any case, the short answer is no, they won't. There is a Worklog task that describes the status of this feature …

[Read more]