MariaDB at FOSDEM: slides, booth questions, etc.

At FOSDEM 2010, MariaDB was represented by Kristian Nielsen and me. Together with Vlad Kolesnikov we’ve manned the joint MariaDB & PBXT stand. I’ve had the main track talk titled “MariaDB: extra features that make it a better branch of MySQL” (slides), and
Kristian had a more general talk titled “Beyond MySQL GA: patches, storage engines, forks, and pre-releases” (slides) in MySQL devroom.

There were no other MySQL-related main track talks, so overall, MySQL ecosystem was represented by one devroom, one stand, and one talk. This is exactly as much as a certain other open source database had, with the exception that our stand didn’t have anything to match the blue plush elephants and pencils and mugs.

I’ve taken notes about questions asked at the stand, here they are:

• The most common question: So how do I upgrade from MySQL to MariaDB? People are pleased with the answer.
• A complaint about that it is hard to get data out of a corrupted innodb database, or do anything about a corrupted database (as I understood the visitor wanted a kind of CHECK/REPAIR TABLE[SPACE] command for InnoDB)
• A request to allow to start/stop the slow query log without restarting the server. The idea is that one doesn’t want to have the slow query log turned on at all times but wants to be able to examine performance problems then he sees them, hence the need to start/stop logging without restarting the server. (UPDATE: it is already possible to do in MySQL/MariaDB. See comments for details)
• A complaint about poor performance of stored procedures. Unfortunately, it was not feasible to figure out what exactly was being slow, stored procedure runtime itself, or cursor implementation, or queries that the stored procedure executed, or something else. I was only able to answer that MariaDB doesn’t have any enhancements in stored procedure handling at this point.
• Does MariaDB have any improvements for VIEW handling? The complaint was about poor performance because MySQL “recalculates VIEWs every time”. I’m not sure what is really the problem here, either it is lack of Materialized VIEWs (with indexes on them?), or known poor optimization in case where VIEW is not mergeable
• Do we have any plans to support transactional DDL statements? (no)
• Does MariaDB have any improvements in query cache? (no)
• Have we in MariaDB fixed a certain MySQL bug (I’ve lost the bug#) with triggers? (no)
• Is it possible to have indexes on MariaDB’s virtual columns? (only when the column is “stored”. indexing a non-stored virtual column would essentially give one functional indexes, and MariaDB doesn’t support them at the moment)

Due to being one of the three people manning the stand I’ve missed most of the MySQL devroom. It would be nice to learn if there were any interesting discussions there.