It's very easy to have an auto_increment column in a table and maintain primary keys. Many people think so, and also they think that MySQL will do the best job for them. With InnoDB, the case is a little different as supposed to be. Basic assumption is that since InnoDB works with row-level locking, combining it with auto_increment should ward off worries. But it is just the beginning.

Let me clarify how auto_increment works. InnoDB maintains the auto_increment value in memory. Good approach. When an insert statement requests the auto_increment value, InnoDB takes the stored value, increment it by one and return. The value in memory is not incremented at this time. This is not bad, because who knows how many rows the insert statement has.

But, this means that InnoDB cannot provide auto_increment values to other threads until this finishes, hence we cannot have concurrent inserts even in InnoDB when using an auto_increment value. …

I have had some comments on my stored functions for XML output from MySql. First of all, publishning the code as a part of a blog post was not a good choice. All xml chars, like < and > must be escaped, and I missed some. I should probably have used the xml_escape function to precess my text...

That is fixed now, and also I have put the function definitions on the MySql forge, here. Please do not hesitate to tell me if you find any errors, or have suggestions for improvement.

Another comment was about the xml functionality of 'mysql --xml'. Yes, there is a function for generating xml output from MySql, I do know that. But if you need to output xml from your application there are a number of problems with it:
1) it has to be invoked from the command line, so you need to start a command shell, redirect output somewhere etc. This is …

After many gruelling hours I've managed to put together reliable methods for decoding the contents of both the Server Handshake packets and Client Credentials packets. Due to the fact that both packet types contain variable length-strings representing details such as the server's version and the client's username (added to the fact that I want to use the MySQL C API) I had to stay away from c++ strings and remain in the realm of null-terminated C-strings. Of course, this meant I had to introduce measures for preventing memory leaks since we're talking about variable length (dynamic!) strings.

That was quite a headache given the amount of complex pointer-passing I'm doing, with segfaults rearing their heads left right and center along the way. However now that I've got some solid methods for decoding, creating and destroying these data types, I'm confident that subsequent work on decoding command and response packets will got far more …

aka, “Better late than never”…..

Back in March 2007, the Boston MySQL User Group (http://mysql.meetup.com/137) watched and heard Brian DeLacey give a tutorial of Ruby on Rails, including its interaction with MySQL using ActiveRecord.

I knew absolutely nothing about Ruby on Rails before attending the presentation, other than Ruby was a language and people were saying that Rails made for easy development. After the presentation, I knew enough to start coding!

Brian is an excellent speaker, and this presentation is long overdue. (I’d tried creating the video before, during and after the MySQL Users Conference back in April, and my application kept crashing. I guess it just needed a break, because I fired it up today and it seemed to save the movie OK. Please let me know if you watch the presentation and something seems wrong).

Enjoy!

…

Back in March 2007, the Boston MySQL User Group ( http://mysql.meetup.com/137 ) watched and heard Brian DeLacey give a tutorial of Ruby on Rails, including its interaction with MySQL using ActiveRecord. I knew absolutely nothing about Ruby on Rails before attending the presentation, other than Ruby was a language and people were saying that Rails made for easy development.

After the presentation, I knew enough to start coding! Brian is an excellent speaker, and this presentation is long overdue. (I'd tried creating the video before, during and after the MySQL Users Conference back in April, and my application kept crashing.  More »

I asked people to share with me their experiences moving to Zimbra, and I've had a great deal of responses. One, in particular, I found interesting from Time Out New York. I glommed onto this one immediately because I reference Time Out whenever I'm in London. It's the best source of information for what's going on.

Jeffrey Vargas of Time Out New York related: [Used with his permission]

Time Out New York is a weekly print publication, so we rely heavily on Macs. Out of 150 computers, about 125 are Macs. Even are servers are Xserves, for a majority of our work.

We've been using Apple's mail services in OS X since 10.2. After a messy migration to OS X 10.3 and several issues with an update from OS X 10.3.8, we were over frustrated with Apple's frugal mail services.

Having upgraded to two new Intel Xeon servers late last year, …

I wanted to write a quick shout-out to congratulate the PostgreSQL development team, the folks at Sun who work with Josh Berkus, and the folks at EnterpriseDB, all of whom contributed to the excellent benchmark results for this quarter's SPECjAppServer2004 benchmark suite. I'm looking forward to seeing Josh at OSCON in a couple weeks and meeting a few more of the PostgreSQL developers than I did last year.

I know that the PostgreSQL developer team has spent a considerable amount of time and effort improving performance bottlenecks and streamlining code for the PostgreSQL 8.2 release, and the benchmarks show the results of that hard work. It's great to see the pressure put on Oracle and the "big guys" from …

Ok…I’ve been crazy busy with job and home stuff. Doesn’t mean I stop thinking about stuff.

• Do we really need another text editor/Personal Information Manager/MP3 player? I monitor Gnomefiles and Portable Freeware RSS feeds and I’m constantly seeing these types of apps being created, promising to be a better than anything out there with whiz-bang features not seen anywhere else. Got news for you, you aint showing us nuttin’ new.
• The First Bank of Delaware needs to DIAF for offering loans at 99.25% interest. That’s right, 99.25%! It’s done through their CashCall marketing arm. Yes. The one offered up by has-been Gary Coleman. They’re preying on people who can’t manage their money.
• MySQL-Proxy is …

Todays most confusing error message award goes to MySQL, for this error(?) message of mysqld_safe when trying to start the mysqld daemon:

db1:/usr/local/mysql# bin/mysqld_safe --user=mysql
Starting mysqld daemon with databases from /usr/local/mysql/data
STOPPING server from pid file /usr/local/mysql/data/db1.pid
070713 14:16:50  mysqld ended

Finding the problem was easy...

db1:/usr/local/mysql# ldd bin/mysqld
        librt.so.1 => /lib/librt.so.1 (0x00002b43be382000)
        libdl.so.2 => /lib/libdl.so.2 (0x00002b43be48b000)
        libpthread.so.0 => /lib/libpthread.so.0 (0x00002b43be58f000)
        libcrypt.so.1 => /lib/libcrypt.so.1 (0x00002b43be6a4000)
        libnsl.so.1 => /lib/libnsl.so.1 (0x00002b43be7d8000)
        libm.so.6 => /lib/libm.so.6 (0x00002b43be8f0000)
        libstdc++.so.5 => not found
        libc.so.6 => /lib/libc.so.6 (0x00002b43bea72000) …

Like an invincible psycho with a knife, Log Buffer is back, with a Friday the 13th issue (”Larry’s Revenge!”). Daniel Fink of OptimalDBA is the lucky one to do this 53rd edition of the weekly review of database blogs. Please read Log Buffer’s homepage and drop me a line if you’d like to [...]