Is mysqlnd stable, is mysqlnd ready for wider consumption? Judging from the latest set of tests: yes!

During the development of mysqlnd, the MySQL native driver for PHP - an alternative to libmysql, a good number of new tests have been written. Let’s see how ext/mysql and ext/mysqli perform when running the test suite. Please note that this is a snapshot and figures might be slightly different when you repeat the test runs: mysqlnd is under constant development and your setup is likely to differ from mine.

Is mysqlnd stable, is mysqlnd ready for wider consumption? Judging from the latest set of tests: yes!

During the development of mysqlnd, the MySQL native driver for PHP - an alternative to libmysql, a good number of new tests have been written. Let’s see how ext/mysql and ext/mysqli perform when running the test suite. Please note that this is a snapshot and figures might be slightly different when you repeat the test runs: mysqlnd is under constant development and your setup is likely to differ from mine.

I have run in to the issue where I wanted to change some configuration on our production MySQL server but did not want to restart MySQL since its in production.  One of the parameters we like to change time to time is the “log_slow_queries” so we can see what queries are slow in production environment.  [...] …

So, I had written a while back: “We currently have a DataMemory of 4GB and IndexMemory of 2GB. Based on the crude methods we have to monitor it, I think we are at about 40% capacity.” Boy, I was wrong.

After that post, I started looking at this more in detail because we were considering buying more RAM “just in case”. I figured out how to use the super secret command “all dump 1000″. The command is not documented in the MySQL documentation that I could find. I did find it in the NDB API documentation before writing this post however. Not sure why I could not find it before.

For those that still don’t know how to use it, simply type “all dump 1000″ from your management console. Then check your cluster log files …

The Apache Friends team is proud again to announce a new version of XAMPP for Linux and Windows. The new version of XAMPP includes fresh, green and up-to-date versions of: PHP (5.2.3) and MySQL (5.0.45). In case of Linux we also upgraded phpMyAdmin to the recent 2.10.3.

To all beta testers: Thanks so much for all your hard work!

Get XAMPP 1.6.3 here

I hereby declare what from now on shall be known as “Jan's Law”:

Whenever a discussion about storage systems arises, the proximity of discussing the amounts of adult content that fits onto such systems reaches one.

I bought a WD MyBook Pro II for my storage and backup needs. The 2x500GB RAID 1 setup provides enough space and safety for me. It is also faster than the internal 2.5" hard drive of my Intel Mac Mini and since Macs can be booted from Firewire drives I thought it'd be a good idea to do just that.

I went to install a fresh copy of MacOS X onto the new drive. The installer happily proceeded and upon reboot, well, the Mini didn't reboot into the new system. The old installation came up. Easy, I thought, just set the correct Startup Volume in the Preferences. No Go.

Luckily, when holding the alt-key while starting up, a Mac shows all available volumes to start OS X from. Relieved, I chose the MyBook volume. A couple of seconds into the startup sequence, the …

Though this is an age old concept, but after seeing the ignorance factor of many regarding this, I thought of writing a bit about it. ROLLUP is a GROUP BY modifier that adds extra rows to the output which contain summary data. At each level of aggregation the aggregated column is filled with a NULL value.

Let's see a small example. I know the values are too small for the data presented, but just to keep it readable.

   1: mysql> CREATE TABLE `rollup_1` (

   2:   `url` varchar(255) DEFAULT NULL,

   3:   `year` int(11) DEFAULT NULL,

   4:   `country` char(2) DEFAULT NULL,

   5:   `visit` int(11) DEFAULT NULL

   6: ) ENGINE=MyISAM DEFAULT CHARSET=latin1;

   7: Query OK, 0 rows affected (0.01 sec)

   8:  

   9: mysql> SELECT * FROM rollup_1;

  10: +----------------------+------+---------+-------+

  11: | url                  | year | …

Mysql AB provides print_stacktrace function inside stacktrace.c.
void print_stacktrace(gptr stack_bottom, ulong thread_stack)

mysqld.cc calls it when segfault happens:
print_stacktrace(thd ? (gptr) thd->thread_stack : (gptr) 0,
thread_stack);

Its basic idea of print_stacktrace is

1. first get current frame pointer fp

take __i386__ for example, fp is
Extended Base Pointer (ebp)

#ifdef __i386__
__asm __volatile__ ("movl %%ebp,%0"
:"=r"(fp)
:"r"(fp));
#endif


+---------+------------------+
| EBP - 4 | local variables |
| EBP | callees EBP |
| EBP + 4 | ret-addr |
| EBP + 8 | parameters |
+---------+------------------+

2. transverse the stack to print the call stack info
/* We are 1 frame above signal frame with NPTL and 2 frames above …