I'm supposed to be working on subquery optimization but I can't get BUG#26630 out of my head.

The bug test case is small and easy to understand: looking at the EXPLAIN:

CREATE TABLE tbl_test( ... ) partition BY range(num) (...);
 
EXPLAIN partitions
SELECT * FROM tbl_co c STRAIGHT_JOIN tbl_test t WHERE t.num=c.num AND reg=8;

..+-------+-------------+------+---------------+------+---------+------+------+-------------+
  | table | partitions  | type | possible_keys | key  | key_len | ref  | rows | Extra       |
..+-------+-------------+------+---------------+------+---------+------+------+-------------+
  | c     | NULL        | ALL  | NULL          | NULL | NULL    | NULL |   17 | Using where |
  | t     | p0,p1,p2,p3 | ALL  | NULL          | NULL | NULL    | NULL |   17 | Using where |
..+-------+-------------+------+---------------+------+---------+------+------+-------------+ …

Several people from Solid gave talks at the Conference. They were centered around solidDB--a storage engine for MySQL. The slides from the most important ones are collected here, and also at the Solid's research site http://research.solidtech.com/myUC07/

"solidDB Storage Engines"
Ari Valtanen, Solid Co-Founder, Senior Vice President, CTO
[ Abstract | PPT]

"Strengthening High Availability in MySQL"
Vilho Raatikka, Solid Software Engineer
[ Abstract | PPT | …

We've been doing a lot of performance analysis of MySQL and SATA disks over the last few days and I wanted to get some thoughts out in the open to see what you guys thought.

Now that Debian Etch is out we're seriously looking at making the jump to a full 64bit OS with 8G of memory on each of our boxes.

This also involves benchmarking SATA and potentially migrating away from MyISAM which, while very trusty, is seriously showing its age for us.

First off is raw IO tuning.

XFS benchmarks show about a 20% performance boost from bonnie++ over ext3. This is pretty obvious. Tuning readahead with 'blockdev' didn't seem to help performance much. SATA seems pretty tuned when compared to hdparm and IDE drives.

After fully tuning it seems we can get about 90MBps out or our disks. Not to shabby. The Linux md driver on RAID 0 didn't seem to boost IO performance much (and I'm pretty disappointed). Even with a 1M chunk …

I can't write I'm just back from MySQL Users Conference both because I'm still in USA visiting customers and because it has ended almost a week ago but I was too busy to write anything about it or post my presentations.

This was my 5th MySQL Users Conference so I met a lot of good friends and spend more time speaking to people when expected (even though still did not speak to everyone I wanted to) and less time attending the sessions.

The Conference was solid and interesting this year while it was not so strictly organized as before. For example even though there suppose to be "Session Buddies" they did not show up on my sessions and on one of them I had to myself remind to Jim Starkey he was 10 minutes into my talk already. The fact all rooms were about the same size was also a problem - many interested sessions were jam packed while other rooms were empty. It is surely exciting to speak with standing audience but I'd prefer …

I was asked the question today, “How do I show the details of a Stored Procedure in MySQL. The SHOW PROCEDURE ‘name’ didn’t work.”.

The obvious answer was SELECT ROUTINE_NAME,ROUTINE_DEFINITION FROM INFORMATION_SCHEMA.ROUTINES, given I like to use the INFORMATION_SCHEMA whenever possible. This lead me to think was is the corresponding SHOW command. A quick manual search got me to SHOW CREATE PROCEDURE.

What was interesting was not this, but the list of other SHOW commands I didn’t know. I did not know about SHOW MUTEX STATUS, SHOW OPEN TABLES and SHOW …

Compiere fork ADempiere claims production quality. Unisys and Forrester release study on open source acceptance. Apelon open sources Vocabulary Server. (and more)

ADempiere becomes first true open source production grade ERP, ADempiere (Press Release)

Independent Research Firm?s Commissioned Study for Unisys Shows Growing Acceptance of Open Source in Business-Critical Applications, Unisys (Press Release)

Apelon Vocabulary Server Now Open Source, Apelon (Press Release)

Survey: open source shows progress in public sector, The Register (Article)

…

Matt’s post on managing the ‘No Open Source’ clause cites stats from the recent Forrester report that shows a perniciously high percentage of respondents are concerned with ‘legal liabilities for copyright and patent infringement” (43% if I read the data properly), and how a dual license strategy takes this issue off the table.

That all makes perfect sense.

But what if the reason dual license open source companies like mySQL are successful is because Enterprises overstate the real risk of using open source software!

Wouldn’t that be ironic: As Enterprises gain awareness and sophistication about open source licensing issues and IP, they become …

We’ve been doing a lot of performance analysis of MySQL and SATA disks over the last few days and I wanted to get some thoughts out in the open to see what you guys thought.

Now that Debian Etch is out we’re seriously looking at making the jump to a full 64bit OS with 8G of memory on each of our boxes.

This also involves benchmarking SATA and potentially migrating away from MyISAM which, while very trusty, is seriously showing its age for us.

First off is raw IO tuning.

XFS benchmarks show about a 20% performance boost from bonnie++ over ext3. This is pretty obvious. Tuning readahead with ‘blockdev’ didn’t seem to help performance much. SATA seems pretty tuned when compared to hdparm and IDE drives.

After fully tuning it seems we can get about 90MBps out or our disks. Not to shabby. The Linux md driver on RAID 0 didn’t seem to boost IO performance much (and I’m pretty disappointed). Even …

This release of the innotop MySQL and InnoDB monitor is a major upgrade in terms of functionality, code quality, and interface consistency. It is the result of me working for over a month to get innotop into shape for the recent MySQL Conference and Expo. Here’s a summary of the changes: Major changes Quick-filters to easily filter any column in any display Compatibility with MySQL 3.23 through 6.0 Improved error handling when a server is down, permissions denied, etc Use additional SHOW INNODB STATUS information in 5.