Since my first post on MySQL transaction descriptors optimization introduced in Percona Server 5.5.30-30.2 and a followup by Dimitri Kravchuk, we have received a large number of questions on why the benchmark results in both posts look rather different. We were curious as well, so we tried to answer that question by retrying benchmarks on various combinations of hardware and dataset sizes, including the ones that are as close as possible to Dimitri’s environment. To put a long story short, the results are fairly consistent with our original post across all test combinations. …

One of the greatest things with working in the MySQL community has been to meet so many people and travel in different countries and cultures. In my last blog post I mentioned how I learned that in Southern Europe it is considered offensive to go too early to meet your customer. As the customer is expecting you to come later than agreed (everyone always does), if you show up too early you are taking away time that he was expecting to still use to prepare for the meeting.

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Somebody asked why you can’t implement MySQL triggers that write information when you want to stop the DML statement, like autonomous procedures in Oracle. The question was a surprise but I didn’t find anything on it, so here’s how you can do it. This is more or less like an autonomous process by leveraging both the InnoDB and MyISAM engine’s behaviors. This post leverages an earlier explanation of MySQL Triggers.

1. First you create a MyISAM table, which is a persistent store that auto commits when you’re other InnoDB tables can be transactionally dependent. Here’s a simple MyISAM logger table.

CREATE TABLE logger
( logger_id         INT UNSIGNED AUTO_INCREMENT PRIMARY KEY
, logger_event      VARCHAR(50)
, logger_table      VARCHAR(50)
, logger_instring   VARCHAR(100)
, …

Just recently did the presentation and Q&A for the Using Perl Stored Procedures presentation at Percona Live 2013.

The presentation has been uploaded:

Using Perl Stored Procedures for MariaDB from Antony T Curtis

(repeat posting because planet.mysql.com didn't notice it the first time around)

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I’m sitting here in the lounge at SFO thinking back on the last week, the majority of which has been spent meeting my new workmates and attending the Percona MySQL conference.

For me it has been as much of a family reunion as it has been about seeing the wonderful things going on in MySQL.

Having joined Continuent last month after an ‘absence’ in NoSQL land of almost 2.5 years, joining the MySQL community again just felt like coming home after a long absence. And that’s no bad thing. On a very personal level it was great to see so many of my old friends, many of whom were not only pleased to see me, but pleased to see me working back in the MySQL fold. Evidently many people think this is where I belong.

What was great to see is that the MySQL community is alive and well. Percona may be the drivers behind the annual MySQL conference that we have come to know, but …

I’ve started poking around the MySQL 5.7.1 source tree (although just from tarball as I don’t see a BZR tree yet). I thought I’d share a few thoughts:

• InnoDB temporary tables. Not REDO logged. What does this mean? It’s a huge step in removing the dependency on MEMORY and MyISAM engines for temporary tables used in query execution. With InnoDB temporary tables there is no reason for MEMORY engine to continue to exist, there is absolutely no way in which it is better.
• InnoDB temp tables aren’t insert buffered
  This probably doesn’t really matter as you’re not going to be doing REDO logging for them (plus things are generally short lived)… but it could be a future area for performance improvement
• The NO_REDO log mode appears to be implemented fairly neatly.
• Improvements in innodb read only mode. What does this mean? Maybe we can finally get rid of the oddity of compressed …

Just recently did the presentation and Q&A for the Using Perl Stored Procedures presentation at Percona Live 2013.

The presentation has been uploaded:

Using Perl Stored Procedures for MariaDB from Antony T Curtis