At the recent leaders summit of world leaders in Oracle, Java and MySQL user communities I gave a presentation on Why Upgrade to MySQL 5.5
This is a more high level overview presentation, specifically designed for Oracle resources with little to no knowledge about MySQL, however it provides a great management approach to the consideration of using the current MySQL GA version.
I have a more detailed technical presentation from last year on Reasons to Use MySQL 5.5.
A week ago I again had the pleasure to give a guest lecture at Tampere University of Technology. I've visited them the first time when I worked as MySQL pre-sales in Sun.
To be trendy, I of course had to talk about the cloud. It turns out every section has the subtitle "...and why it is more difficult for databases". I also rightfully claim to have invented the NoSQL key-value development model in 2005.
I see that MySQL 5.5.21 has just been released. This sounds interesting. I’m mainly running 5.5.16 which has been broadly stable, but I have been caught by a few important issues which 5.5.21 fixes according to the change list:
These together with a few earlier fixes after 5.5.16 are certainly interesting to me, so I’m eager to try out 5.5.21 and see how it fairs.
I’m in the process of getting the tests passing for the 0.03 release of NIST::NVD::Store::SQLite3 wherein our hero imports the CWE data and cross-indexes it with CVEs and CPEs.
Follow along and suggest some patches. I’m developing on Debian Wheezy, but I would very much like input from devs on other platforms.
http://git.colliertech.org/?p=NIST-NVD-Store-SQLite3.git;a=summary
cjac@foxtrot:/tmp$ time git clone http://git.colliertech.org/git/NIST-NVD-Store-SQLite3.git Cloning into 'NIST-NVD-Store-SQLite3'... real 0m32.757s user 0m0.200s sys 0m0.088s cjac@foxtrot:/tmp$ ls NIST-NVD-Store-SQLite3/t/data/ cwec_v2.1.xml nvdcve-2.0-test.xml
Publish your patches and I’ll fetch them, or you can submit them in udiff format and I’ll review/apply. Thanks for playing along!
[edit 20120216T1456 -0800] …
[Read more]In a recent rant on Why I think SQL_MODE is useless…, I wanted to counteract this statement with why we MUST all use SQL_MODE, even with the inherit flaws.
The fundamental principle of a database is to restore and retrieve data. When I can insert data into the database and then I select this data it is different, this is fundamentally wrong. This is a loss of essential data integrity, something a database should NEVER do.
SQL_MODE solves the problem of “silent truncation” in most instances, and produces an all important error. As pointed out, the SQL_MODE has several limitations, however the benefits do out way the risks. Quality control on source code can reduce the limitations, but no amount of coding can stop the CRUD that comes out of the database without some SQL_MODE settings.
I would ask two more …
[Read more]I published an SQLite3 storage back-end to NIST::NVD on the CPAN. It’s pretty quick. About as fast as the DB_File one, but without the down side of being tied to DB_File. It shouldn’t be too difficult to re-factor this code to any DBI-based database. MariaDB anyone?
I know it works on Debian. The nightly CPAN test results should come back shortly and I’ll find out how well it works on other platforms.
MySQL, like a lot of other software, has many knobs you can tweak. Most of these knobs may affect behaviour, but more importantly most affect the memory usage of the server, so getting these settings right is very important.
Most of MySQL’s memory is really used just as a cache, in one form or another, information that otherwise is on disk. So ensuring you have as large a cache as possible is important. However, making these memory sizes too large will trigger the server to start swapping and possibly can cause it to crash or cause the kernel to kill the process when it runs out of memory. So that’s something we want to avoid.
Certain settings affect memory allocation on a per connection/thread basis, being bounded by thread_cache_size and max_connections. If you configure for the worst behaviour (max_connections) you may end up not actually using all the memory you have available, memory which normally could be …
[Read more]As a consultant I often use the MySQL Reference Manual to provide additional information for clients. I am very happy to recognize the quality of the content in the MySQL documentation, but why is the searching of the manual so, so bad?
While reading the General Security Issues section of the MySQL 5.5 manual, I performed a search for “CREATE USER”. I was not asking for anything abstract, this is an actual SQL command. I was rather horrified to find that the results could not even list the appropriate manual page in the first page of results.
I am not an expert in full-text search, however it does not take a rocket scientist to realize that a SQL keyword, the title of a page, in the language of the current page (English) and the current version of the Manual (5.5) should be …
[Read more]
You might have noticed that this blog changed name and
URL. Instead of having one single blog for everything, I
decided to split my blogging activities in two separate
blogs.
If you're interested in MySQL, Oracle, Databases, Business
Intelligence, Open Source, Cloud, etc. this is the place to be.
Blog's new name is Data & Co.
A big "Thank you!" to David
Stokes who moved all the planet.mysql.com references to
the old blog to this new one.
On the other hand, if you'd like to read about communication,
marketing, advertising, PR, soft skills, etc. feel free look at
Publicime. Please see the introduction
of my new blog …
If you’ve been tuning your MySQL database and have wondered what effect the innodb_flush_method settings have on write performance, then this information might help. I’ve recently been doing a lot of baseline load tests to show performance differences between localdisk and the new SAN we’re deploying. Since we run InnoDB for everything in production, and writes are very heavy, I decided to run comparison tests between two identical servers to find the best setting for innodb_flush_method. We have the following specs for the hardware: