Today I fixed a bug in our application that was interesting to figure out. Without a ton of detail, the gist is that if you convert a datetime to unix timestamp in MySQL:

mysql> select UNIX_TIMESTAMP('2006-10-28 04:00:00'); 
+---------------------------------------+
| UNIX_TIMESTAMP('2006-10-28 04:00:00') |
+---------------------------------------+
|                            1162022400 |
+---------------------------------------+
1 row in set (0.00 sec)

And then add 24 hours to it:

mysql> select 1162022400 + (60*60*24);
+-------------------------+
| 1162022400 + (60*60*24) |
+-------------------------+
|              1162108800 |
+-------------------------+
1 row in set (0.00 sec)

And then convert it back to a datetime it magically loses an hour:

mysql> select FROM_UNIXTIME('1162108800');
+-----------------------------+
| FROM_UNIXTIME('1162108800') |
+-----------------------------+
| 2006-10-29 03:00:00 …

All -

I’m pretty excited that 5.1.12 is now out! Thanks to everyone who has been helping us test all the great new features in 5.1 - I hope you’ll download 5.1.12 and keep up the good work. One thing that I especially like about the 5.1.12 beta is that it has the highly requested feature of being able to dynamically turn on/off the general and slow query logs, which makes impromptu tracing of SQL much easier.

Download 5.1.12 and let me know what you think.

Thanks again for supporting MySQL!

When I was upgrading from 4.0 to 4.1 I noticed the internal 'mysql' database had tables of reference data. This allows clients to get help directly from the server instead of browsign the online docs at mysql.com. This is convenient when you are not connected to the internet.....

The MySQL Community team led by Jay Pipes is putting together MySQL Camp, an "un-conference" that will be held November 10-12 in Mountain View, California. This is not a fancy formal gathering, just an opportunity for smart folks from the MySQL community to gather together, share notes, ideas, best practices, do some brainstorming and maybe hack on some code!  There's a range of proposed topics but half the fun will be seeing what comes together on one unstructured weekend.  If you're in the bay area, check it out. This is a low-key, non-corporate event designed for folks who want to participate and not just be observers.

• MySQLCamp.org: Home, …

When I was upgrading from 4.0 to 4.1 I noticed the internal 'mysql' database had tables of reference data. This allows clients to get help directly from the server instead of browsign the online docs at mysql.com. This is convenient when you are not connected to the internet.....

A Federated Table is a table which points to a table in an other MySQL database instance (mostly on an other server). It can be seen as a view to this remote database table. Other RDBMS have similar concepts for example database links.

class Guard {
public:
Guard(NdbMutex *mtx) : m_mtx(mtx) { NdbMutex_Lock(m_mtx); };
Guard(NdbLockable & l) : m_mtx(l.m_mutex) { NdbMutex_Lock(m_mtx);
};
~Guard() { NdbMutex_Unlock(m_mtx); };
private:
NdbMutex *m_mtx;
};

Traffic at www.mysql.com has continued to increase and over the last few months, we've broken into the top 500 websites according to Alexa.  While the Alexa rankings are not perfect, they do enable relative comparisons between sites and over time.  For example, MySQL's traffic surpassed Oracle's back in April of this …

It's been an interesting last few weeks for me and MySQL. One of my side projects (I currently have three, two are MySQL-focused) provided an opportunity to really dig into the MySQL source code (5.1 tree). For many of my evenings for the past few weeks I've been hacking away, fiddling with the kind of MySQL customizations I've previously only seen other folks do.

The list of customizations:

• 
  
• build a user defined function (UDF) that gets dynamically loaded into MySQL
  
• add a new native (built-in) function to the MySQL source code
  
• create a storage engine using the pluggable storage engine architecture
  
• create a new SHOW command
  
• create a new virtual table in the INFORMATION_SCHEMA database
  

And of course, while I was in there I threw …

Swedish telecom vendor Teligent has employed several different databases in its products in the past -- including Oracle, Berkeley DB and Microsoft SQL Server -- but now the company has chosen MySQL Cluster to be the standard for its Teligent P90/E platform, on which its products are based. Teligent supplies innovative network services like voice message systems, Mobile data and VoIP to operators like British Telecom, Deutsche Telekom, TeliaSonera and Vodafone.