The latest release has a lot of great improvements that you’ll be sure to enjoy.
As usual you can download here: http://kontrollsoft.com/software-downloads
It’s been just over three months since the April 2009 MySQL Users Conference and Expo. It took a while for the files to be processed, and then uploaded to www.technocation.org, and then I found out that the online streaming was not working properly. So I started playing with things, re-encoding some videos, updating the software, but to no avail.
Just as I was about to give up I got notification that Technocation, Inc. was accepted into YouTube’s not-for-profit program, which allows movies larger than 10 minutes to be uploaded and viewed advertisement-free.
So then I had to upload the videos to YouTube and add descriptions.
So with no *further* delay, here are all the videos from the 2009 MySQL Conference and 2009 MySQL Camp:
The brief description — just the playlists:
Conference …
I ran into this little problem today; when dividing two whole
number the result MySQL gave me was nowhere near as precise as I
needed it to be. The values were truncated which caused me some
errors in my application.
Example:
mysql> select 1*0.00001;
+-----------+
| 1*0.00001 |
+-----------+
| 0.00001 |
+-----------+
Ok, that looks fine. Let's do the same thing using
division:
mysql> select 1/100000;
+----------+
| 1/100000 |
+----------+
| 0.0000 |
+----------+
Oops! What happened?
The issue is that the maximum precision of the result value
depends on the number of decimal places in the arguments. Since
the second version uses two whole numbers, the result uses the
default number of decimal places, which is 4. So you really have
to take care to make sure you're getting the precision you …
I’ve been editing a task description in our worklog:
WL#706 Add EXPLAIN support for other statements
(UPDATE/DELETE).
Currently MySQL supports EXPLAIN SELECT but there have been requests for EXPLAIN UPDATE, EXPLAIN DELETE, and so on. In fact it’s my impression that the proposition in WL#706 (transform the statement to a SELECT and then say EXPLAIN SELECT) is not what people want. But that’s okay, while a worklog is an early stage we allow simple ’solutions’ that might disappear later.
I'm pleased to announce the release of SQL Bench, the benchmark
test suite the comes standard with MySQL, now as a separate
project targeted for testing any database. I have pulled it out
as a separate project so I can modify and improve it faster. With
this release, I have successfully used it for testing both
Drizzle and MySQL. Other RDBMSs, I have yet to test.
Modifications
I modified the connection test, which part of it is to connect,
run a single query for one row, disconnect, to iterate only
20,000 times vs. 100,000 times. The reason for this is to allow
this test to reasonably test databases that use TCP sockets. When
I added Drizzle support to SQL Bench, upon running the connect
test it would fail inexplicably. After some serious testing, it
was realized that since Drizzle uses TCP sockets, even when
connecting to localhost, that the connect test would fail because
of the result of sockets being kept around in …
Image by Sebastian Bergmann via Flickr
I had a quick chat with Michael Widenius today. He is on vacation so tried to keep the call short. Essentially spoke about two topics, Oracle & an update on Maria.
The Monty Program has 15 staff now. Their focus is getting the MariaDB branch of MySQL ready for release, I understand they have a target of next month (August) for this release. The Maria storage engine has been delayed for the time being with the focus being on the branch release instead. PBXT and XtraDB will two …
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Installation of MySQL Server on Linux (RedHat Enterprise Linux
5)
The recommended way to install MySQL on RPM-based Linux
distributions is by using the RPM packages. The RPMs that
MySQL/Sun provide to the community should work on all versions of
Linux that support RPM packages and use glibc 2.3. You can
download it from
http://mirrors.sunsite.dk/mysql/downloads/mysql/5.1.html
Checking if MySQL is already installed & would be uninstalling it
to install latest MySQL version
[root@localhost mysql]# rpm -qa | grep -i '^mysql-'
MySQL-python-1.2.1-1
mysql-5.0.22-2.1.0.1
mysql-server-5.0.22-2.1.0.1
mysql-connector-odbc-3.51.12-2.2
Un-installing older version of MySQL
[root@localhost mysql]# rpm --nodeps -ev
MySQL-python-1.2.1-1
[root@localhost mysql]# rpm --nodeps -ev
mysql-5.0.22-2.1.0.1
[root@localhost mysql]# rpm --nodeps -ev …
A really simple best practice:
Make sure there are NO mysql servers connected to the Cluster
while you do the restore!
It can cause the restore to fail badly and potentially even your
cluster.
Also, make sure (if you use disk data) to remove all data files
in the datadirs of the data nodes as they are not removed when
doing an --initial ... I have written a bug report about
that...
(i will update the severalnines/config scipts to include this
best practice!)
Restarts are required for certain, infrequent maintenance activities. Note that there is no loss of service while a single node restarts.
When a data node restarts, it first attempts to load the data into memory from the local log files and then it will catch up with any subsequent changes by retrieveing them from the surviving node(s) in its node group.
Based on this, you would expect the time taken to restart a data node to be influenced by:
The times will also be influenced bycertain configuration parameters, performance of the host machine and whether the multi-threaded data node (ndbmtd) is being used.
To provide some insight into how these …
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