Some hidden goods in MySQL 5.5

The announcement of MySQL 5.5 released as GA has outlined the improvements in this version, which indeed has enough good new features to excite most any user.
There are two additions, though, that were lost in the noise of the bigger features, and I would like to spend a few words for each of them. The first addition is something that users of stored routines have been waiting for since MySQL 5.0. No, it is not SIGNAL and its close associate RESIGNAL, which have been publicized enough. I am talking about the stored routine parameters, for which now there is a dedicated table in the information_schema.
Let's see an example, with a simple procedure that uses three parameters.

drop procedure if exists add_to_date ;
create procedure add_to_date(in d date, in i int, out nd date)
deterministic
set nd = d + interval i day;

This works as expected in both 5.1 and 5.5. (Never mind that it's redundant. I know it. It's only for the sake of keeping the example short).

call add_to_date('2010-12-15',10,@new_date);
Query OK, 0 rows affected (0.00 sec)

select @new_date;
+------------+
| @new_date |
+------------+
| 2010-12-25 |
+------------+
1 row in set (0.00 sec)

The difference starts to show when you want to deal with this procedure programmatically. If you need to find out which parameters are expected by this procedure, your only option in MySQL 5.1 is parsing the result of SHOW CREATE PROCEDURE add_to_date. Not terribly difficult in any scripting language, but a hassle in SQL.
In MySQL 5.5, instead, you can easily get the routine parameters with a simple query:

select parameter_name, parameter_mode,data_type from information_schema. parameters where specific_schema='test' and specific_name= 'add_to_date' order by ordinal_position;
+----------------+----------------+-----------+
| parameter_name | parameter_mode | data_type |
+----------------+----------------+-----------+
| d | IN | date |
| i | IN | int |
| nd | OUT | date |
+----------------+----------------+-----------+
3 rows in set (0.00 sec)

Speaking of the information_Schema, there are more goodies that were not emphasized enough. The Innodb engine that you find in the server is the evolution of the InnoDB plugin that ships with MySQL 5.1. Only that it is now built-in. What many people forget to mention is that the plugin (and thus the current InnoDB engine in 5.5) comes provided with its own InnoDB-specific instrumentation tables in the information_schema.

show tables like 'innodb%';
+----------------------------------------+
| Tables_in_information_schema (innodb%) |
+----------------------------------------+
| INNODB_CMP_RESET |
| INNODB_TRX |
| INNODB_CMPMEM_RESET |
| INNODB_LOCK_WAITS |
| INNODB_CMPMEM |
| INNODB_CMP |
| INNODB_LOCKS |
+----------------------------------------+
7 rows in set (0.00 sec)

This is the same set of tables that you may have seen if you have worked with the InnoDB plugin in 5.1. In short, you can get a lot of the info that you used to look at in the output of SHOW ENGINE INNODB STATUS. For more information, you should look at what the InnoDB plugin manual says on this topic.
I don't know if the tables can replace the SHOW ENGINE INNODB STATUS. Perhaps someone can comment on this issue and provide more information?

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What if Jessus Born Today..??? MUST SEE..!

The Antikythera Mechanism... Built With LEGO

I'll be honest, I had little clue about what the "Antikythera Mechanism" was. Although I'd heard of it, I didn't know who built it, when it was built or why it was built.
As it turns out, in 1901, divers off the coast of the Greek island of Antikythera found a device on board a shipwreck dating back over 2,000 years. Not much was known about the "device" until, in 2006, scientists carried out X-ray tomography on what remained of the complex artifact.

According to the recent Nature article Ancient astronomy: Mechanical inspiration, by Jo Marchant:

"The device, which dates from the second or early first century BC, was enclosed in a wooden box roughly 30 centimetres high by 20 centimetres wide, contained more than 30 bronze gearwheels and was covered with Greek inscriptions. On the front was a large circular dial with two concentric scales. One, inscribed with names of the months, was divided into the 365 days of the year; the other, divided into 360 degrees, was marked with the 12 signs of the zodiac."

The device -- which sounds like something that belongs in a Dan Brown novel -- is an ancient celestial computer, driven by gears to carry out the calculations and dials to accurately predict heavenly events, such as solar eclipses. The technology used to construct the device wasn't thought to be available for another 1,000 years.
According to Adam Rutherford, editor of Nature, the science journal has a long standing relationship with the Antikythera Mechanism. In a recent email, Rutherford pointed to a video he had commissioned in the spirit of continuing Nature coverage of this fascinating device. But he hadn't commissioned a bland documentary about the history of the Antikythera Mechanism, he'd commissioned an engineer to build the thing out of LEGO!
The result is an engrossing stop animation production of a LEGO replica of this ancient celestial calculator. For me, this video really put the device in perspective. The Greeks, over 2,000 years ago, built a means of predicting the positions of the known planets, the sun, even the elliptical motions of planetary orbits. They'd drawn inspiration from the Babylonians (according to new research reported on by Nature) and re-written the history of what we understand of the ancient civilization's technical prowess.
Sadly for the ancient Greeks, the Antikythera Mechanism was lost for 2,000 years at the bottom of the ocean and only now are we beginning to understand just how advanced this fascinating piece of technology truly is.

Watch this video, it's awesome:




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