And this has been said before but I can’t help but say it again…

In the latest Oracle Magazine, Tom Kyte and Ari Kaplan’s columns both tout one of 11g’s new features – the “server results cache” or “query result cache” (as the authors referred to it, respectively) . They both describe it as a “great new feature”. Neither happens to mention that MySQL has had this since version 4.0. It rankles me. It looks like there are a lot of truly “great new features” in 11g; let’s give credit for this one where it’s due.

This release is part of the unstable 1.5 branch. Its features will ultimately go into the stable 1.6 branch. You can download it from the innotop-devel package.

The major change is I've ripped out the W (Lock Waits) mode and enabled innotop to discover not only what a transaction is waiting for, but what it holds too. The new mode that replaces W is L (Locks). My last article goes into more detail on this.

This article shows you how to use a little-known InnoDB feature to find out what is holding the lock for which an InnoDB transaction is waiting. I then show you how to use an undocumented feature to make this even easier with innotop.

The following is the current list of available JDBC 4.0 drivers:

• Java DB/Apache Derby
• MYSQL Connector/J 5.1
• Oracle 11g
• inet software for Microsoft SQL Server(Merlia driver) and for Oracle (Oranxo driver).
• Atinav aveConnect 4.0 for Microsoft SQL Server
• DataDirect 3.7 has also introduced some JDBC 4.0 features

Yes, it's a hard habit to break. Having that glass walled tall building replaced by a humbled "home office" that could resemble anything from a kitchen table to wine cellar to converted bedroom or even garage.

But if you're starting from scratch with seed funds at best or going into round A and the lease isn't signed yet, take a closer look! You might like what you see and the investors, shalt you have them already, might like your thinking.

The savings in gasoline, commute tempers, lack of road rage, blood pressure medications, makes this look very "green" and hip today. Even Al Gore (no, I'm actually not a fan) would endorse it as a global warming take action frontier type go getter decision. Go MySQL!

Fact is, we do it because it just makes sense! Most, but not all, of our employees work from home at MySQL.

The benefits of not having to commute to work saves a ton of time, and having …

We had an unscheduled test of our backups last night. Point-in-time recovery using a mysqldump and binary log files worked fine (thank goodness).

I’m used to thinking of (Oracle) exports being one thing, and point-in-time recovery (using hot backups) another. Maybe there’s a way to do a “PITR” in Oracle using an export, rolling forward using timestamps rather than SCNs… Don’t know. I know that with MySQL you can do it.

Last night we had some user-generated data corruption on a production server. The database was relatively small (a few Gig), so, after stopping the database and restarting it with ––skip-networking, I imported it from the latest daily mysqldump. Although I didn’t use ––master-data for the mysqldump (we had some locking issues with that in the past) I knew the time that the mysqldump had been started.

I did a little investigation into the binary log files using …

One of the marketing guys mentioned to me today that he saw Adobe CEO Bruce Chizen on CNN this morning reporting on their Q3 financial results.  The company grew by 41% year over year with record quarterly revenue of $851 million and operating income of $255 million. (Yes, those are quarterly figures!)  Chizen attributed the success to the strength of the recently released Creative Suite 3 and Acrobat.

MySQL is used by over a hundred different software ISVs and hardware OEMs for everything …

We are currently working on Cool Stack 1.1.1 which will have the following components updated, in addition to fixing known bugs :

• Apache 2.2.6 : Add mod_proxy, mod_fcgid, SMF support
  
• PHP 5.2.4      : Add dtrace extension, add new fastcgi version for use with non-Apache webservers
• APC 3.0.14
  
• Suhosin 0.9.20
  
• MySQL 5.0.45: Add SMF support
  
• Perl 5.8.8       : Add Sys:Syslog, DBI, DBD-mysql extensions
• memcached 1.2.2
• squid 2.6
• tomcat 5.5.23

I would love to get feedback on this. Is your favorite module/extension missing ? Are there bugs/issues you have run into that haven't been reported on the forum ?

26th of September, just after HighLoad conference I will have full day MySQL master class.

This time we will talk about Innodb Architecture and Performance Optimization and when will discuss some MySQL Performance Optimization and Scaling case studies from audience (or some of from my MySQL Consulting Practice if there would not be enough of them). As usually I'll try to keep it very interactive and will try to answer any other MySQL Performance, Scaling and High Availability questions you might have.

Entry posted by peter | 3 comments

Add to: …

Every so often you need to perform sort results retrieved from MySQL when your WHERE clause goes beyound col=const values which would allow MySQL to still use second portion of the index for the order by. Ranges as well as IN lists make this optimization impossible, not even speaking about index merge optimization. Lets look at this example:

PLAIN TEXT SQL:

1. CREATE TABLE `utest` (
2.   `c1` int(10) UNSIGNED NOT NULL,
3.   `c2` int(10) UNSIGNED NOT NULL,
4.   `ord` int(10) UNSIGNED NOT NULL,
5.   KEY `c1` (`c1`,`ord`),
6.   KEY `c2` (`c2`,`ord`)
7. ) ENGINE=MyISAM DEFAULT CHARSET=latin1
8.  
9. mysql> EXPLAIN SELECT * FROM utest WHERE c1=5 OR c2=5 ORDER BY ord DESC LIMIT 10 \G
10. *************************** 1. row ***************************
11.           …