The announcement last month of Oracle to acquire Sun continues to warrant a lot of discussion over exactly what Oracle will do with MySQL. Only time will tell what will happen with the official product, however it is important to remember that MySQL is GPL, there will always be a free version of MySQL available for popular LAMP stack products such as WordPress and Drupal and new and existing startup’s will continue to use MySQL.

This announcement will see Oracle resources begin to better understand and evaluate MySQL. As a resident MySQL Expert, I also have a strong background in Oracle having also worked for Oracle Corporation. I have also delivered several successful one day and half day workshops on MySQL/Oracle related content including:

• 2009 - Best Practices …

So lets test some different configurations and try and build some best practices around Multiple SSD’s:

Which is better? Raid 5 or Raid 10?

As with regular disks, Raid 10 seems to performance better ( accept for pure reads ).  I did get a lot of movement test to test like with the 67% read test -vs- the 75% or 80% tests. But all in all RAID 10 seemed to be the optimal config.

Should you enable the controller cache? One of the things I have found in my single drive tests is that “dumb” controllers tend to give better performance numbers then “smart” controllers. Really expensive controllers tend to have extra logic to compensate for the limitations of traditional disk. So I decided to play with some of the controller options. The obvious one is cache on the controller.

Some tests showed substantially better performance when the disk cache was disabled ( both read & write ).

If better …

MySQL has had basic support for Geospatial Data since 4.1, but has lacked some of the features of the OpenGIS specifications since then. The good news is, this is rapidly changing. Our own Holyfoot has been hammering away at WorkLog #1327, to provide precise functions for our GIS support.

Even better, it’s fast. How fast? Well, the good people at Oki Labs, apart from having implemented several new GIS functions for MySQL, have done some benchmarking, and it’s looking good. If you’ll excuse the cliched comparison to Postgres, here are the response times (seconds) of MySQL GIS vs. PostGIS in Oki’s test:

Sometimes you need to run EXPLAIN on long running queries. Most time EXPLAIN takes few seconds, but sometimes it looks like it executes query itself instead of using statistic.

Like in the example following:

mysql> explain select \* from (select sleep(10) as foo) bar;
+----+-------------+------------+--------+---------------+------+---------+------+------+----------------+
| id | select_type | table      | type   | possible_keys | key  | key_len | ref  | rows | Extra          |
+----+-------------+------------+--------+---------------+------+---------+------+------+----------------+
|  1 | PRIMARY     | <derived2> | system | NULL          | NULL | NULL    | NULL |    1 …

Sometimes when you do profiling you can see number like this in timestamps. Periodically in our patches there was Query_time: 18446744073709550.000 in slow.log file (well, it was fixed recently, but still appears in other places).

I faced this problem several years ago when only 2-core AMD Opteron systems appeared and I noticed sysbench getting crazy showing query execution time 18446744073709550.000 or like this.

Obviously this is unsigned integer which was received by subtraction bigger number from smaller.
But how it can be if we use:

start_time = clock_gettime(CLOCK_THREAD_CPUTIME_ID, &tp);
...
query_execution
...
end_time = clock_gettime(CLOCK_THREAD_CPUTIME_ID, &tp);

total_time = end_time - start_time;

How we can get query executed in negative time ? It would be too good to be real :).

After some research I found the reason, and it is …

Yesterday, the ebox and warp staff went to Alagon (25km from Zaragoza) to have a very nice BBQ, or should I say WBQ?

We had delicious food, drinks, music, a swimming pool and weather couldn’t be more perfect.

And also we ended up with a new guest in our home

View …

We got an interesting question on the documentation list the other day, which basically asked if we provided a service that listed changes to specific pages in the manual.

While I like the idea of such a service, the mechanics of making such a service work are very difficult. To start with, and to re-iterate something I have to explain again and again:

the MySQL documentation is rebuilt up to 10 times *every* day

We don’t have set schedules for when we release changes. We don’t bundle changes up and then produce a new reference manual on a set day of the month, or week. If I make a change to the documentation right now, there is every chance that you would see that change in the live docs at http://dev.mysql.com/doc within 3 hours, and for the PDF format, possibly even within the hour.

Yep, it happens that quickly. And that happens every day of the year …

So far I am pretty excited about using Oracle SQL Developer with MySQL. I spent about ten minutes installing Oracle SQL Developer, the MySQL J Connector and setting up SQL Developer to connect to MySQL.I've only been using it a few minutes and so far its been great to work with. Oracle SQL Developer has matured into a nice interface so its been really fun to work with. In terms of ease of

Installing Oracle SQL Developer was way too easy!Installing Oracle SQL Developer is pretty straight forward to install. You will need to install the Oracle SQL Developer software and the MySQL J Connector (JDBC driver). It then requires about two minutes to point and click through the setup of the MySQL connection using the JDBC driver in SQL Developer. Oracle SQL Developer has the following

The tasty new logo

We’ve been busy lately here at WordPress.com — we’ve had an announcement of a new or updated feature for you every day this week. Today, you’re getting a two-fer!

Earlier this week, we announced VideoPress, the great new video feature for WordPress.com. Now VideoPress has its own home on the web at VideoPress.com. We’ve also got a great video introduction created by our company auteur Michael Pick, so be sure to head over and check it out. We’ll be continuing to add features to VideoPress, including support for WordPress.org users, so stay tuned to VideoPress for all the latest. …