As the summer in many parts of the world starts, not only the snow is thawing, many bloggers are also coming out of hiatus and the database blogosphere is seeing new sensational activity. This Log Buffer Edition includes blogging tidbits from Oracle, SQL Server and MySQL. Enjoy reading Log Buffer #270. Oracle: Oracle’s Timeline, Copious [...]

A short while after I fixed the legacy bug that prevented temporary MyISAM tables from using the dynamic record format, I got an email from Davi Arnaut @ Twitter. It turned out that Twitter needed to fix the very same problem, but for the case when INFORMATION_SCHEMA temporary tables use MyISAM.

In short, INFORMATION_SCHEMA tables provide access to database metadata. Despite their name, they are more like views than tables: when you query them, relevant data is gathered from the dictionary and other server internals, not from tables. The gathered data is stored in a temporary table (memory or MyISAM depending on size) and then returned to the user.

The reason Davi emailed me was to let me know that he had further improved the fix for temporary MyISAM tables to also enable the use of dynamic record format for …

Following my series of posts on testing different SSD, in my last post I mentioned that SATA SSD performance is getting closer to PCIe cards. It really makes sense to test it under MySQL workload, but before getting to that, let me review the same workload on Fusion-io ioDrive PCIe card. This is yet previous generation of Fusion-io cards, but this is the one that has biggest installation base.

Driver information: Fusion-io driver version: 2.3.10 build 110; Firmware v5.0.7, rev 107053

Following the format of previous benchmarks, first is random write async 16KB case.

We can see some wave-like pattern with throughput 350-400 MiB/sec.

Random reads, async:

…

Read the original article at Ten things to remember about MySQL backups

1. Use Hot Backups

Hot backups are an excellent way to backup MySQL.  They can run without blocking your application, and save tons on restore time.  Percona’s xtrabackup tool is a great way to do this.  We wrote a how-to on using xtrabackup for hotbackups.

Just because we love hot backups using xtrabackup doesn’t mean mysqldump isn’t useful.  Want to load data into Amazon RDS?  Want to isolate and load only one schema, or just one table?  All these great uses make mysqldump indispensable.  Use it in …

A few weeks ago was the Percona Live: MySQL Conference & Expo. As in years past, I have recorded videos. Scroll down to see the 15 videos I am able to share. Very special thanks go to my fellow Mozillian espressive of the Mozilla WebDev team who was generous enough to make this look very nice, as CSS is not my specialty.

Unfortunately, Percona will not let me share the tutorial videos I recorded – which is odd, since O’Reilly had no problems with me recording tutorials in 2008 (memcached tutorial), 2009 (part 1 and …

Ever come accoss a situation where you have to load a flat text file into MySQL with data provided in single column! Say, your data to be loaded in table…

The post Load columnar text file into MySQL table first appeared on Change Is Inevitable.

I had to benchmark an EC2 instance to see whether a database could be safely moved to it. It is a good practice, which helps avoiding surprises when an instance or its storage are allocated in a noisy neighborhood, where the neighbors use so much resources that it affects the performance of our MySQL database. It is understandable that one can never get very reliable results on EC2, this is a shared environment after all, and that some fluctuations should be expected, however it is still good to know the numbers. I started my benchmarks and everything seemed fine at first, but then sometimes statistics I was getting started looking quite odd.

I was running the benchmarks on a High-CPU Extra Large Instance and couldn’t see any reliability in the results at all. I mean, in one moment I was getting poor throughput and horrible response times only to see it improve a lot a few minutes later. I ruled out a possibility that it could be …

Come see Doron Levari speak about MySQL scalability at Seattle MySQL meetup: http://t.co/qdsUkSsG

The recording of yesterday’s webinar, as well as a PDF of my slide deck, is now available. You can watch the recording and get the slides here.

I got a lot of questions, and did not have enough time to answer all of them, so let me try to answer some of the remaining questions here.

Q: Isn’t it possible to take all the locks required in the beginning to prevent dead locks? So you would get a lock wait instead of a dead lock. No, that would cause blocking that would defeat the purpose of the tool.

Q: When you say bail out, what does that mean? Does the tool clean up (i.e., remove table / triggers?) About cleanup.. What about manual aborting a run. will that cleanup ? Q: dose the tool exit gracefully while interupted? The tool doesn’t clean up the temporary table or triggers. It is designed …

I got a really intriguing email today. As you might imagine, I get a lot of email offering to advertise, or trade links, or guest post, etc etc. But this is the most compelling one I’ve ever gotten: I came across your blog /blog/2009/03/13/50-things-to-know-before-migrating-oracle-to-mysql/ a few weeks ago as while conducting research for a website that I contribute to. The website aims to look at the progressive areas of early childhood psychology.