Tandem-Forum has signed an agreement with MySQL AB to become an Authorized MySQL Training Center (AMEC) and will immediately begin to offer MySQL 5.0 training in Moscow, Russia.

New review up at http://www.openwin.org/mike/index.php/books/mysql-phrasebook/.

Short version: I like it.

Eventually every database system hit its limits. Especially on the Internet, where you have millions of users which theoretically access your database simultaneously, eventually your IO system will be a bottleneck.

Question: How can I monitor the basic database related system information for my MySQL host?

Answer: The following monitoring utilities can be used to montitor your MySQL host and database:

The MySQL documentation team has released a companion manual to accompany the new single installer for all MySQL GUI tools in the form of a unified manual for all GUI tools, available as a PDF at http://downloads.mysql.com/docs/guibook-en.pdf.

Should be worth keeping on hand if you are a heavy GUI user.

dhh committed a patch for activerecord to make it work with mysql 5 that was subsequently reverted because it broke things on postgres and sqlite.

obviously we?d like ruby on rails to work with mysql 5, but because there was no test case committed along with either of these changes, i don?t really know the root cause of the problem. dhh claims it is the changes that made mysql conform to the standard sql join syntax, but i can?t evaluate that because i can?t reproduce the problem.

any activerecord gurus want to …

Ever wonder what all those binaries with names starting in “ndb” were doing in mysql/bin? Not surprisingly, they’re MySQL Cluster monitoring, utility, and demonstration programs, and after a couple of fun-filled weeks of experimenting with them (and asking a few of the usual sorts of silly questions I’m know for asking in the right quarters) I’ve been able to document most of them in a new Cluster Utility Programs section of the MySQL Manual (I’ve linked to the 5.1 version, but they’re available in 4.1 and 5.0, too).

If you’ve not looked at these before, check them out. A couple of them — like ndb_waiter and ndb_desc — are handy for monitoring a MySQL Cluster or getting information about NDB tables and other Cluster data objects; others — such as …

In our project (the secret merlin project) at MySQL I had to fetch entries from the table which specified by a time-span with a start and a end time:

root@localhost [merlin]> select * from dc_INTEGER; 
+---------+------------+-------+---------------------+---------------------+
| data_id | collect_id | value | begin_time          | end_time            | 
+---------+------------+-------+---------------------+---------------------+
|       1 |          3 |     0 | 2005-10-12 13:28:04 | 2005-10-13 13:43:25 |
|       2 |          1 |    94 | 2005-10-12 15:46:01 | 2005-10-13 10:22:28 |
|       3 |          1 |    95 | 2005-10-13 10:22:28 | 2005-10-13 11:15:59 |
|       4 |          1 |    94 | 2005-10-13 11:15:59 | 2005-10-13 13:43:31 |
+---------+------------+-------+---------------------+---------------------+

The ranges never overlap for the same collect_id.

Now the problem was: How does the query look like if I want to fetch time-span …