Posts Categorized: Technical Blog
Here are the slides from my presentation at RMOUG 2010. I am not sure how much sense all this will make without my comments. We may do it in a webinar if there is sufficient interest. Regardless I will probably be doing it again at some point in the future.
If I told you that your database had a ratio of temporary tables written to disk of 20%, you might think “aha, my database is slow because of a lot of file I/O caused by writing temporary tables to disk!”. However, that 20% ratio may actually mean a rate of 2 per hour — which is most likely not causing excessive I/O. To get a sense of this concept, and also how mysqltuner works, I will show the lines from the mysqltuner default configuration that deal with temporary tables written to disk.
I recently granted ALTER access in MySQL so a user could run the ALTER TABLE command . However after I granted the necessary privileges, the user was still not able to perform the tasks needed. Then I realized what the issue was and how to fix it.
Good afternoon and welcome to another edition of the usually, mostly, kind of weekly news for System Administrators. I was on a much needed holiday for the last couple of weeks. Many thanks to Tim for filling in on the last one. What with clients’ priorities and February being a short month, we did not have the cycles to get a blog out last week, and this one will be short because, frankly, the IT news world has been a bit slow of late. With that I shall cease my preface and move on to . . .
Hello and welcome to Log Buffer #180. Time’s a-wastin’, so let’s go!
Applying binary logs to a MySQL instance is not particularly difficult, using the mysqlbinlog command line utility. Turning off binary logging for a session is not difficult, from the MySQL commandline, if you authenticate as a user with the SUPER privilege.sometimes you want to apply binary logs to a MySQL instance, without having those changes applied to the binary logs themselves. One option is to restart the server binary logging disabled, and after the load is finished, restart the server with binary logging re-enabled. This is not always possible nor desirable, so there’s a better way, that works in at least versions 4.1 and up
I was sad that last year there was no community dinner, and I missed the one the year before when Jonathan Schwartz and Rich Green made an appearance. This year I am determined not to miss it, and so I am calling for a community (pay-your-own-way) dinner on Monday, April 12th, at Pedro’s
For many, CPAN is a Canadian Prairies-sized field of modules where it’s darn hard to separate the wheat from the chaff. While the CPAN Ratings service is the principal and official way CPAN tries to rank its distributions, for me at least, it doesn’t quite scratch the itch. Consequently, for a while now I’ve been playing with ideas on how the rating could be improved. What I came up with so far is a very minimal system going straight for the goods. And now, since I’ve had a three-day week, I decided to give the idea a try and implement a prototype.
You have found the 179th edition of Log Buffer, the weekly review of database blogs. Welcome. Enjoy your stay. We begin with . . .
There are those that are very adamant about letting people know that using INFORMATION_SCHEMA can crash your database. Of course they leave out one extremely important piece of information: you can actually figure out how dangerous your INFORMATION_SCHEMA query will be, ahead of time, using EXPLAIN. Here’s how.