In MyISAM, we do have LOAD INDEX INTO CACHE. In InnoDB this does not work. For benchmarking I often require a way to preload the innodb_buffer_pool with the primary key and data after a server restart to shorten warmup phases.

According to Blackhole Specialist Kai, the following should work: CODE:mysql> create table t like innodbtable;
mysql> alter table t engine = blackhole;
mysql> insert into t select * from innodbtable; Another win for the unbreakable BLACKHOLE storage engine.

MySQL’s latest advertising campaign (called “The 12 Days of Scaleout“) is getting a bit of a kicking in the MySQL blog space.

I am sure that this is slightly uncomfortable for the MySQL team, but at the same time the team is lucky that people who care about MySQL still take the time to explain what they don’t like.

Perhaps it would be a good time for them to go back and add some meat to the case studies?

…

As I am happy to report a number of people have responded on my initial challenge of 3+3 lessons on building open source business, I wanted to post the links so far, enjoy:

Mårten Mickos, CEO of MySQL

Stephen Walli, an Open Source Expert

Ignacio Correas, CEO of Warp

Stephen O’Grady, Redmonk

Michael Tiemann, President of Open Source …

Zimbra is today's featured scale out example as part of our 12 days of scale out series.  I've always had a soft spot for Zimbra since I first met CEO Satish Dharmaraj a couple of years back at the first Red Hat Summit in New Orleans. Their ambition is significant: they offer a plug-in replacement for Microsoft exchange that is open-source, cross-platform and more scalable. Zimbra Collaboration suite can handle multiple hundreds of thousands of email …

MySQL AB today published a case study on Wikipedia's successful use of the MySQL database to help manage its massive popularity. The winner of the 2005 'MySQL Application of the Year' Award, Wikipedia is today's featured user in the vendor's "Twelve Days of Scale-Out" educational initiative. The campaign is live at www.mysql.com/scaleout.

Microsoft and Linspire sign collaboration agreement. Ohloh enhances online service for open source contributors. Open-Xchange launches new version of collaboration server. (and more)

Microsoft and Linspire Collaboration Promotes Interoperability and Customer Choice, Micrososft / Linspire (Press Release)

Ohloh Launches New Online Service to Connect People Who Create and Use Open-Source Software, Ohloh (Press Release)

Open-Xchange Gives Feature Boost to Collaboration Server, Open-Xchange (Press Release)

…

I was reading only last week the notes from Wikipedia: Site Internals, Configuration and Code Examples, and Management Issues Tutorial by Domas Mituzas at the recent 2007 MySQL Conference. I didn’t attend this session, like a lot of sessions too much good stuff at the same time.

It’s obviously taken a while to catch up on my reading, but with the present MySQL 12 days of Scale-Out I thought I’ll complete my notes for all to see.

If you have never used Wikipedia well, why are you reading this, you should spend an hour there now. Alexa places Wikipedia in one of the top 10 visited sites on the Internet.

…

I was asked recently to confirm a consistent state of data in a non-transactional MySQL table after a failing statement updating multiple rows did not complete successfully.

Hmmm, this is what I did.

• Created a MEMORY table
• Populated with some data, and a Primary Key
• Updated the Primary Key so that it failed with a Duplicate Key Error after updating only half the rows
• Confirmed that the rows that were updated, were, and the rows that were not updated, were not

DROP TABLE IF EXISTS mem1;
CREATE TABLE mem1(
i1  INT UNSIGNED NOT NULL PRIMARY KEY,
c1 CHAR(10) NOT NULL,
dt TIMESTAMP)
ENGINE=MEMORY;

INSERT INTO mem1(i1,c1) VALUES (1,'a'), (2,'b'), (3,'c'), (4,'d'), (5,'e');
SELECT * FROM mem1;
+----+----+---------------------+
| i1 | c1 | dt                  |
+----+----+---------------------+
|  1 | a  | 2007-06-14 17:26:29 |
|  2 | b  | 2007-06-14 17:26:29 |
|  3 | c  | 2007-06-14 …

Damien Seguy had an interesting observation on my use of self joins for generating rolling sums yesterday:

What about using a user variable to make the rolling sum from the beginning? Something simple enough like this :

set @sum := 159;
// to start with the original number of post, or 0 if you prefer.
set @mn := 0;
// for the month number
select @mn := @mn + 1 as MonthNumber Month, Added, @sum := @sum + Added as RunningTotal from ResultListing1;

Damien, of course, is correct, that I could have used a user variable like the above to generate the rolling sum, instead of using a self join. However, there are some complications. First, let's look at what happens if I rewrite Lenz' original GROUP BY statement to include a user variable to calculate running totals:

Finally! Some MySQL ActionScript drivers. We have a couple choices right now, so bookmark the one you like - asSQL, Asql.