User Defined Function

I really like this new toy called UDF. So I try to provide some more, hopefully useful, functionality.

A list of what I have done up to now you can find here:

• Query and change InnoDB spin_wait_delay: udf_spin_wait_delay.tgz
• Send message to the MySQL error log: udf_log_error.tgz, works also with MySQL 5.1.42

If you have some more suggestions, please let me know. If you need some special features as UDF talk to our consulting services if they can implement it.

Get and set InnoDB spin_wait_delay

mysql> …

I really like this new toy (for me) called UDF. So I try to provide some more, hopefully useful, functionality.

The newest extension I like is the possibility to write to the MySQL error log through the application. Oracle can do that since long. Now we can do this as well…

A list of what I have done up to now you can find here:

• Query and change InnoDB spin_wait_delay: udf_spin_wait_delay-5.1.30-linux-i686-glibc23.so (md5 807c6bc09b5dc88a8005788519f2483a, BIN … kbyte)
• Send message to the …

In one of my previous posts I was writing about how to read other processes memory
[ 1
]. As an example I tried to get the value of the hard coded MySQL internal InnoDB variable spin_wait_delay (srv_spin_wait_delay).

In this example we were using gdb or the operating system ptrace function to retrieve this value. This method has the disadvantage that it is pretty invasive.

When I was working on a customer support case I had the idea to solve this by the much less invasive method of User-Defined Functions …