One thing we were guessing at with Massimo yesterday is, if you store
large blobs as disk data, how much will they consume DataMemory and
IndexMemory (primary key, each "chunk" has a hidden primary key, first 25x bytes
of blob stored in memory...)?

My empirical test showed that about 2% of the total size of blobs is needed for RAM
(25% of that is IndexMemory).

IMHO this is close to negligible, but in many situations not negligible
at all (may have close to TB of disk data -> 20GB of RAM needed for
disk data).

Also note that this is a minimum figure. If you actually have something
else than the blob (like other indexes) you of course use much more RAM.

The test was:
CREATE TABLE `jpgtest` (
`id` int(11) NOT NULL,
`jpg` blob,
PRIMARY KEY (`id`)
) TABLESPACE ts_1 STORAGE DISK ENGINE=ndbcluster;

One thing we were guessing at with Massimo yesterday is, if you store
large blobs as disk data, how much will they consume DataMemory and
IndexMemory (primary key, each "chunk" has a hidden primary key, first 25x bytes
of blob stored in memory...)?

My empirical test showed that about 2% of the total size of blobs is needed for RAM
(25% of that is IndexMemory).

IMHO this is close to negligible, but in many situations not negligible
at all (may have close to TB of disk data -> 20GB of RAM needed for
disk data).

Also note that this is a minimum figure. If you actually have something
else than the blob (like other indexes) you of course use much more RAM.

The test was:
CREATE TABLE `jpgtest` (
`id` int(11) NOT NULL,
`jpg` blob,
PRIMARY KEY (`id`)
) TABLESPACE ts_1 STORAGE DISK ENGINE=ndbcluster;

Sun Microsystems today announced that Aftonbladet is now running the majority of its business on MySQL Enterprise™.

Aftonbladet is the largest daily newspaper in the Nordic region, with about 1,209,000 readers a day, and Aftonbladet.se is the largest online news site in the region with approximately 4.2 million unique visitors per week.

One command, which few people realize exists is SHOW OPEN TABLES - it allows you to examine what tables do you have open right now:

PLAIN TEXT SQL:

1. mysql> SHOW open TABLES FROM test;
2. +----------+-------+--------+-------------+
3. | DATABASE | TABLE | In_use | Name_locked |
4. +----------+-------+--------+-------------+
5. | test     | a     |      3 |           0 |
6. +----------+-------+--------+-------------+
7. 1 row IN SET (0.00 sec)

This command lists all non-temporary tables in the table-cache, showing each of them only once (even if table is opened more than ones)

In_use show how many threads are …

As Giuseppe just reminded MySQL 4.0 is reaching its end of life in about 2 weeks from now. When it becomes unsupported by MySQL via normal support agreements together with 3.23 version.

At Percona we do not have such restriction and we will continue to support your environment even if you're still on MySQL 4 or 3.23 (we indeed do have customers which are still using 3.23 now)

What does it mean for you in practice ? This means we will continue helping you with issues you're having with MySQL 3.23 or 4.0 and will be happy to backport bug fixes to MySQL 3.23 and 4.0

Supporting MySQL 3.23 and MySQL 4.0 environment is indeed more expensive than current MySQL versions because we can't relay on Sun/MySQL doing any work with bug fixes plus more work is often needed because these versions have lower …

I've been asked to make some reports recently for some people in my company.Almost all of them are quite heavy and hit the database pretty hard.The thing is that these reports are usually generated once or twice a month, but they process a year's worth of data. Every time they are generated, they really upsets my poor production MySQL database.
I was thinking if there maybe could be a better way to just save the processed data in a table and update it every now and then.
So.. this is what I did:

1. I created a table that keeps the aggregated results from the report.
   
2. I added to the start of the SQL statement "INSERT INTO reports.thistable SELECT (the worlds most intensive SQL query) ;"
   
3. At this point I realised that I need a bit extra help determining which parts of the data should be updated and …

I have been spending a few days looking into optimisation for a few of our products, the biggest of which is Intellichat, which this great MySQL function is soon to be used for. Intellichat handles thousands of chats every hour, we average at about 190,000 chats a day, which is increasing daily. Every one of these chats holds information about the chat, from the Agent name, through the the IP address that launched the chat. This data allows us to provide detailed statistics to our customers from which Agent name converts best to which Country generates the most sales for their product.

*** Please note that all data sizes below are taken from the PHPMyAdmin row size and not the individual data size as listed in the mysql manual ***

Since starting out, I had always used a char(15) which uses 16 bytes to store ’192.168.0.1′. Since …

Hi all,

Are you aware of the fact that you can use NetBeans IDE for programming with Python? It's still early in the game, but it's true. We've already set up a quick tutorial for Python at http://wiki.netbeans.org/NetBeansPythonTutorial.

As mentioned, it's still early, but efforts are already underway to provide tutorials that feature the following:

• Python and Django
• Database Interaction (SQLAlchemy, mysqldb)
• GUI programming (wxPython, pyGTK)
• PyQT4

I'll let you know more as the story develops.

Cheers!

--James