I went looking for the MySQL 5.4 documentation today, but alas I could not find it. In particular, I went looking for the list of changes between 5.1.34 and 5.4.1.

If 5.4.1 is beta then it should definitely have documentation, at least in beta form. This is especially true in light of the Sun MySQL conference keynote kind of dangling a carrot on a stick, as it were, with a question to the audience about opening the docs up under the GPL. The comments system also needs updated too. I think that if public comments are available on the web site, then those comments should have a rating system attached so that crappy, wrong and useless manual comments can easily be filtered. But I digress.

So, Sun, when are going to release all the MySQL documents under the GPL? Is it going to be in the MySQL 5.4 time frame, or in some far off hazy future? And why are there no 5.4 documents available



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When I filed Bug#39197 replication breaks with large load with InnoDB, flush logs, and slave stop/start, I genuinely thought that it was a serious problem. I was a bit puzzled, to tell the truth, because the scenario that I was using seemed common enough for this bug to be found already.
Anyway, it was verified independently, but there was a catch. The script in the master was using SET storage_engine=InnoDB to create the tables necessary for the test. That looked good enough to me. The script was indeed creating InnoDB tables on the master. The trouble was that the "SET"



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I’ve mentioned a number of times that the documentation repositories that we use to build the docs are freely available, and so they are, but how do you go about using them?

More and more people are getting interested in being able to work with the MySQL docs, judging by the queries we get, and internally we sometimes get specialized requests.

There are some limitations - although you can download and access the docs and generate your own versions in various formats, you are not allowed to distribute or supply that iinformation, it can only be employed for personal use. The reasons and disclaimer for that are available on the main page for each of the docs, such as the one on the 5.1 Manual.

Those issues aside, if you want to use and generate your own docs from the Subversion source tree

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Martin Brown’s blog shows a pretty good way of navigating the MySQL Reference Manual. It’s worth noting, however, that finding the different topics has been a lot easier since mysql.com started using a Google appliance for its search.

I use the documentation all the time and have been doing so for years (I won’t claim that I can remember +2000 pages worth of ever-changing content). A few years back, I stopped using the search box on dev.mysql.com because the result sets were enormous, with lots of unrelated references. My technique was to do a Google site search:

For replication use the expression: replication

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Hooray! The MySQL reference manual has a new search system. It now uses a Google Appliance and the results should be a lot better. The old system was not very helpful. It used to break config variables into multiple words and search on them individually and give a billion results I didn’t care about. I’ve just tried to search for some things like key_buffer_size and got results I think are very useful.

I love the MySQL manual. It is a great example of quality software documentation. As someone recently mentioned, it is not released under a Free license though — that would be a great improvement, too!

When did this change happen, by the way? Maybe it’s been there for a while and I just missed it because I grew accustomed to

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When I was on the MySQL Documentation team one thing started to become apparent to me: the MySQL Reference Manual was exactly what it claimed to be: a document better suited to referencing than teaching new users. I make very good use of it because I know MySQL, I know what it can do, and all I want is the right syntax for what I am trying to use it for.

I saw a need for a User Guide, something well suited to new users who were not experienced with MySQL and potentially with DBMSes in general. As a side project I started working on a chapter of what could eventually be a MySQL produced user guide, lacking the depth of the reference manual but more suitable for newer users. This first chapter was on Indexing and while I think it showed promise, I left MySQL AB shortly after completing it.

Fast forward to today, where I see a blog post by

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While doing a standard audit for a new client, I recommended a few changes to get better performance. Because I had several changes, I used the documentation at

http://dev.mysql.com/doc/refman/5.0/en/server-system-variables.html

and found that innodb_flush_log_at_trx_commit is a dynamic variable. I was surprised, because most operations dealing with file sizes and operations are not dynamic. But the client proceeded with:

set global innodb_flush_log_at_trx_commit = 2;

and got:

ERROR 1193 (HY000): Unknown system variable 'innodb_flush_log_at_trx_commit'

So I searched for others who may have had the same error, and ended up getting an unintentional googlewhack. Well,

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I tend to use MySQL from the interactive command line shell quite a bit (SSH to your db server and type the command mysql to start). I noticed today that there is a pretty extensive built in help system in this command.

You can access it by typing help COMMAND, so for instance if you type help ALTER TABLE you get a quick reference for constructing an ALTER TABLE statement.

If you can't remember what command you want to use, then typing help contents is your friend. It will output:

For more information, type 'help item', where item is
one of the following categories:
Administration
Column Types
Data Definition
Data Manipulation
Functions
Geographic features
Transactions

So if your looking for that command that outputs all the columns in a table, but don't know what it's called, you

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Back in July, we made an Eclipse documentation plug-in of the MySQL manuals available for users to download.

In truth, the Eclipse documentation format is actually just HTML; you have to combine the HTML with a plug-in manifest that details the documentation, version number etc so that the documentation is loaded and identified as a valid plug-in element when Eclipse is started.

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Well, it’s been completed a few weeks now, but I’ve finally reworked the Connector/MXJ and Connector/J sections of the MySQL Reference Manual, which in turn means the Connectors chapter has been completed.

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One of the ongoing problems with documentation at MySQL is that it is getting ever larger.

Not only is the size of the docs increasing, but the formats and languages that we support is increasing too, and that is making it more and more difficult to effectively list them and make sure they are available.

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Earlier this week I released the revamped Connector/NET documentation. This is part of the wider Connectors chapter rework, which I’m currently finishing by doing the Connector/J and Connector/MXJ documentation.

Connector/NET provides a full ADO.NET compatible interface to MySQL and is compatible both the Windows .NET and Mono installations.

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We had a great question from a reader yesterday:

Is there a todo/nice-to-have list anywhere for MySQL documentation? Or perhaps a list of Devs who require documentation support? Or is all documentation a function of the core Documentation team?

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Probably the most frequently asked question to the docs team at MySQL from the public is ?I want to translate the manual into [insert language]?. That language can be anything from one we already have, through to some comparatively obscure suggestions.

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I noticed this piece from Johan Andersson on Writing NDBAPI programs?connecting to MySQL Cluster last week, which shows you how to use the NDBAPI?the programming interface to the MySQL Cluster system. By coincidence, we enabled the NDBAPI documentation today. It consists of two elements:

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This week, and specifically today, marks a minor milestone in my employment at MySQL?I?m finally a full time employee, no longer on probation. It has also been probably the busiest week since I started at MySQL, except for the week spent at the developers? conference in Sorrento.

Why so busy?

Because I?ve spent many hours deep in the build process that actually generates the documentation, partly to address some existing errors, but also to improve the documentation after some new content was added. In summary, the following major steps were made this week:

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At the developers conference this year, held in Sorrento, Italy, I was fortunate enough to meet and have dinner with some Italian MySQL users?some of whom had travelled from Rome to be with us that evening at a lovely traditional Italian restaurant just off one of the main squares.

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Documentation is a vital part of any application, proprietary or free software, as it is often the first way to communicate with users about the application or software and how it should be used. I also think it tends to be one of the areas most taken for granted; most users expect it to be there and often forget just how much effort goes into producing it.

Many users also complain about the documentation itself. Often this is because it?s been written by programmers and, as a rule, they really aren?t that great at writing documentation that is particularly human readable.

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As I mentioned here, I?m a member of the documentation team at MySQL, a job I started back in April. I?ve just completed a major tranche of documentation, and thought it would be interesting to let you guys know exactly what happens in a typical day for a member of the documentation team.

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