Archive for the ‘MySQL’ Category
Replication tutorial notes – part 2
This is a continuation of the MySQL User Conference replication notes part one. The session is opening up talking about failover. The shared disk in this case is drbd. DRBD is a fine product for replicating block devices of single disk systems. It’s made redundant by raid and doesn’t provide as much protection as binary [...]
Replication tutorial notes – part 1
I’m attempting to live blog corrections and notes while sitting in the replication tutorial. Lars is covering available options in MySQL replication. I’m going to attempt to cover some recommended best practices and things that are possible to do in MySQL but should be avoided. Please keep in mind that I’m writing this during the [...]
Innodb handler_delete and handler_update status
I woke up this morning to a nice surprise. Peter Zaitsev from MySQL Performance Blog mentioned my fix for a crash in MySQL. Thanks Peter! That reminded me that I need to write this post about another fix. A storage engine is called a “handler” in MySQL internals. Handler events are per row at the [...]
ref or null join type crash and patch
While working with a client we found a query that can crash MySQL. It has to do with ref_or_null outer joins where the table contains a null value. MySQL fails to tell the storage engine to initialize the index before reading from it. It crashes when used with MyISAM tables but it could result in [...]
MySQL Enterprise Registration Emails
[Updated: 2008-03-05 Jeremy writes to tell that I left out the provenscaling.com contact form submission on the 21st and the blank email with a pdf on the 27th] [Updated: 2008-03-26 Rob Young from MySQL AB sent me an email on the 17th saying, "We are currently working to implement PayPal to cut down on the [...]
innodb_log_file_size
In Issue 3 of MySQL Magazine Peter Zaitsev writes, ” I would set [innodb_log_file_size] to 256 megabytes for small sized boxes up to 5% of the total memory on the big boxes.” I tend to set my log file size to around 128M. Depending on your system setting the log file size around a few [...]
MySQL 5.0.48 proof that the MySQL release cycle is completely broken.
When I received and email almost two years ago about a announcement that MySQL was going to release and enterprise product I was very excited. I was looking forward to a redhat style model of vetting releases in the community then offering a proven stable version to paying customers. I saw it as a great [...]
MySQL bugbot and status changes
MySQL Bug Tracker I realize that MySQL is in a transitional phase making it’s development more transparent to the community so this entry isn’t really a rant but something that will hopefully ease the transition. The public MySQL bug tracker doesn’t seem to have any way to view the history of status changes to a [...]
tests and mysql-test sub directories
Recently I’ve been making more modifications to the MySQL source. Part of making modifications is testing them. For years I’ve been curious why there are both tests and mysql-test sub directories in the source tarballs. Arjen Lentz tells me that tests is old and that mysql-test is the current testing framework. This makes sense since [...]
set sql_log_slow=0 to control the slow query log.
Currently there isn’t a good method to control sending individual queries to the slow query log. Typically this isn’t an issue. It becomes an issue when using very short query times and importing sql files. The slow query log doesn’t have a limit on the length of queries it will write to a log. If [...]