I'm pleased to announce the release of Memcached UDFs for MySQL. This release contains the ability to now pass expiration values. For instance, you can:

select memc_set('keyabc', 'somevalue')

or

select memc_set('keyabc', 'I die in 10 seconds', 10);

The functions that now have this ability are:

memc_set()
memc_set_by_key()
memc_append()
memc_append_by_key()
memc_prepend()
memc_prepend_by_key()
memc_add()
memc_add_by_key()
memc_replace()
memc_replace_by_key()

You can download the latest archive from http://patg.net/downloads/memcached_functions_mysql-0.5.tar.gz

Also, mercurial repository at …

Liveblogging: Extending MySQL by Brian “Krow” Aker

Brian wins the award for “most frequent great quotes during a talk”.

Before MySQL 5.1 a UDF was the only way to extend MySQL.

All you need in a UDF is: init() execute() deinit()

my_bool id3_parse_init(UDF_INIT *initid UDF_ARGS *args, char *message)

UDF_ARGS tell you about incoming args
char *message is the output that might return
args->arg_count is the # of args

WARNING: use STRICT mode in MySQL, otherwise there are tons of silent failures.

“When you work on databases you start to put everything in databases. Tip, don’t put a DVD into a database, because really long BLOBs aren’t actually supported….”

In MySQL 5.1, you can now install plugins (example is memcache_servers plugin):

mysql> INSTALL PLUGIN memcache_servers SONAME …

The MySQL User's conference will be held in less than a month from now!!!

This year there is quite a good number of sessions on adding your own functions and procedures, such as:

• 
  
• Advanced Stored Procedures
  
• A Tour of External Language Stored Procedures for MySQL
  
• Code Generators for MySQL Plugins and User Defined Functions (UDFs)
  
• …

Recently, I came upon Baron Swartz's (xaprb's) great now_usec UDF:
http://www.xaprb.com/blog/2007/10/30/how-i-built-the-now_usec-udf-for-mysql/

I use an Intel Macbook Pro for my primary development environment. GCC on OS X has some interesting quirks. Usually to compile a UDF on GNU/Linux I use the following command line:

gcc -fPIC -Wall -I/usr/include/mysql -shared -o udf_now_usec.so udf_now_usec.cc

When I tried to execute the above on my OS X box, I got some errors:

$ gcc -fPIC -Wall -I../include -shared -o udf_now_usec.so udf_now_usec.cc
i686-apple-darwin8-gcc-4.0.1: unrecognized option '-shared'
/usr/bin/ld: Undefined symbols:
_main
___gxx_personality_v0</b>
collect2: ld returned 1 exit status

The …

This release contains bug fixes and new features. Click through to the full article for the details. I'll also write more about the changes in a separate article.

My posts lately have been mostly progress reports and release notices. That's because we're in the home stretch on the book, and I don't have much spare time. However, a lot has also been changing with Maatkit, and I wanted to take some time to write about it properly.

UDF_LUA

You are tired of writing your UDFs for MySQL in C or never wanted to write them in C at all ? How about writing them in lua ?

LUA is - easy to learn - easy to embed - easy to use

and not to forget lua has extensions for everything: - LuaSocket - how about some HTTP requests ? - LuaSQL - connecting back to the MySQL Server ? - ...

UDF_Lua is registered in the MySQL Forge.

functions

As example we want to read the real startup time of the errorlog.

-- we are run with the permissions of the mysqld
-- …