The latest from the MySQL community

I had found pile of MySQL and PostgreSQL benchmarks on various platforms which I have not seen before. Very interesting reading.
It does not share too much information about how MySQL or PostgreSQL was configured or about queries. Furthermore MySQL and PostgreSQL has a bit different implementations (ie SubQueries avoided for MySQL) so do not just compare it directly.

It also does not mention if Innodb or MyISAM tables are used - it turns out Both are used in the benchmark. This is CPU bound benchmark with working set fitting in memory.

MySQL and PostrgreSQL Scalability on Xeon Woodcrest, Opteron and Niagra
Pretty interesting to see how PostgreSQL scales just as systems should scale in theory - gradually goes up with number of threads about matches number of Cores/Threads and stays at this level at higher concurrency. MySQL with Innodb …

Recently I stumbled over a posting on the German MySQL Forum from a user that accidentally removed all table files from a MySQL Server's data directory with a misbehaving shell script. He was surprised to find out that the server happily continued to serve requests and his web site was still fully operational, even though /var/lib/mysql/<database> was completely emtpy! The reason for this in a nutshell: the rm command only removed the reference to the table files from the database directory, the files itself were not removed from the file system yet as the mysqld process still had the files opened. So as long as a process keeps a file open, the kernel will not release the disk space occupied by the file and it will remain intact, albeit no longer visible.

Of course, the user was now desperate to recover the deleted tables files and was …

Recently I stumbled over a posting on the German MySQL Forum from a user that accidentally removed all table files from a MySQL Server's data directory with a misbehaving shell script. He was surprised to find out that the server happily continued to serve requests and his web site was still fully operational, even though /var/lib/mysql/<database> was completely emtpy! The reason for this in a nutshell: the rm command only removed the reference to the table files from the database directory, the files itself were not removed from the file system yet as the mysqld process still had the files opened. So as long as a process keeps a file open, the kernel will not release the disk space occupied by the file and it will remain intact, albeit no longer visible.

Of course, the user was now desperate to recover the deleted tables files and was …

MySQL 5.0 introduces improved SQL modes, which can fine tune the way your server behaves. If you are a long term MySQL user, you may be familiar with the speed for accuracy trade-off. MySQL has a default for each field, and guesses a value when you don't provide an appropriate one when inserting or updating. If this behavior is not acceptable to you, you can now tell the server to be less permissive. Check out an article by Robin Schumacher, where this concept is explained thoroughly.

If you look at the manual, though, you will see that the SQL modes are quite a few, and you may be tempted to combine some of them to control every tiny part of the server …

So the first ever Phoenix MySQL Meetup finally happened tonight. Four of us went to The Yardhouse to sit around and talk geek talk about MySQL and related topics. Hopefully more will come to future meetings. The focus seemed more social than technical, comparing notes on individual backgrounds and occupations. We'll have to see how it evolves as it grows. It'll be interesting seeing what the core group is and what the common interests, an opportunity to compare notes and do some networking of the social variety.

Alfresco has published the results of their enterprise content management benchmark using MySQL 5.0 running on 64-bit Red Hat Enterprise Linux (RHEL). The benchmark uses a 10 million document repository across 10,000 folders and Alfresco was able to demonstrate linear scalability in a real-world scenario. The benchmark demonstrates online performance of batch load with mixed concurrent read and write operations under different user loads with different machine configurations.  The benchmark was validated by Optaros, a consulting firm that specializes in open source project implementations.

Alfresco's design has been implemented in a modular, de-centralized fashion in order to enable highly efficient scale-out and the benchmarks showcase the efficiencies they have achieved.  More details are available from Alfresco in their …

Alfresco, MySQL and Red Hat Deliver First Open Source JSR-170 Benchmark, Alfresco (Press Release)

Corel WordPerfect Office To Support Open Document Format and Microsoft Office Open XML, Corel (Press Release)

Open-Xchange Publishes ‘The End of FUD’ Position Paper, Open-Xchange (Press Release)

CollabNet unveils new global community for collaborative software development, CollabNet (Press Release)

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The other day I did a blog post on ethernet latency.

The next morning I was number two in Google for this search term. I was actually planning a blog post about how quick I owned the keywords and how blogs are doing a great job at SEO.

Five minutes ago I did a search and I'm not even on the first page!

What is on the first page? Well my post as it was re-syndicated from MySQL Planet (which isn't even a permalink to the real content btw).

I'm not on the second page either. Rojo pushed me down with their RojoLink of my content.

I am on the third page mind you but it's not the link to the post but a link to my blog.

What's going on here? …

ZRM for MySQL requires binary logging to be enabled on the MySQL server to do incremental backups. Enabling binary logs has minimal impact on MySQL performance. But, in an active database, the binary logs can grow to hundreds of gigabytes or even terabytes.

ZRM of MySQL has multiple plugin interfaces to customize the backup and recovery process to user environment. One of the plugin interfaces is the post backup plugin. The binary logs are no longer required after a backup. The post backup plugin can purge the binary logs after the backup. This will allow the system administrators to balance between the need for …

Ok, here’s an evil idea for you. Say Oracle wanted to hurt MySQL financially but still look like a community player.

Simply take the Oracle Linux move and extend it to an Oracle Managed fork of the MySQL GPL code. Keep the APIs for storage engines and development and throw developers at improving the internals in some areas that need it, release more regularly than the new Community Edition, only under the GPL.

Oracle could sell support for their GPL edition to make some money, though the department as a whole might operate at a financial loss. The gain is PR and control of course.

How does it hurt MySQL? Well, one of the big reasons for Community v. Enterprise MySQL is to provide differentiation to get GPL compliant users to pay subscription fees. You take away the pain the Community edition provides, you take away the incentives of buying the Enterprise edition.

Mmm, so deliciously evil… I think I need to buy …