What if you could evaluate, deploy and maintain a Data Warehouse (DW) and Business Intelligence (BI) solution for up to 90% less than the cost of proprietary software? What if you can find a solution that has been adopted by customers in all industries and is technically sound and scalable?

You can, with open source Data Warehousing from MySQL and Business Intelligence from Pentaho.

Join this webcast to find out about real world BI/DW deployment strategies that that offer you robust capabilities, yet with a lower total cost of ownership (TCO).

The MySQL and Pentaho solution has been proven in diverse deployments, from small companies to large enterprises. The subscription support model aligns customer and vendor interests, lowering both your costs and project risks. Join this webcast and learn how to be successful in your BI/DW projects. We will show you how MySQL and Pentaho can easily provide a complete …

As I had written earlier in Understanding InnoDB MVCC, I am trying to understand why InnoDB is taking a lock on data during an UPDATE when I do not expect this to happen.

Not wanting to go looking at the InnoDB source code to understand the problem, I’m endeavouring to possibly use existing MySQL monitoring to try and understand the problem better. In this case, I’m going to investigate SHOW ENGINE INNODB STATUS first. An old but still relevant article for reference is SHOW INNODB STATUS walk through. The MySQL High Performance book is also a good starting reference.

I’ve just installed 5.1.36 on a new Linux 64 bit laptop for this test.

For now all I’ve done is ensure the innodb_buffer_pool_size is sufficient …

Multi versioning concurrency control (MVCC) is a database design theory that enables relational databases to support concurrency, or more simply multiple user access to common data in your database.

In MySQL the InnoDB storage engine provides MVCC, row-level locking, full ACID compliance as well as other features.

In my understanding of database theory, access to modify independent sections of unique data (e.g. UPDATE) under MVCC should fully support concurrency. I have however experienced a level of exclusive locking under Innodb.

I wanted to clearly document this situation so I could then seek the advice of the guru’s in InnoDB Internals such as Mark Callaghan, Percona and the Innodb development team for example. I’m happy …

There was small delay in our releases, part of this time we worked on features I mentioned before:
- Moving InnoDB tables between servers
- Improve InnoDB recovery time
and rest time we played with performance trying to align XtraDB performance with MySQL 5.4 ® and also port all performance fixes to 5.0 tree.

So basically we made: new split-buffer-mutex patch, which separate global buffer pool mutex into several small mutexes, and ported some Google IO fixes.
Here are results what we have so far. As usually for benchmarks I used our workhorse Dell PowerEdge R900 with 16 cores and 32GB of RAM and RAID 10 on 8 SAS disks. And again as usually our tpcc-mysql scripts with 100W …

Unlike COUNT(expression), COUNT(DISTINCT expression) is not a distributable function. That is, the expression can not be computed by looking at only the changed rows in the table change logs.



The following view can not be FAST refreshed with Flexviews today:

SELECT a a_alias, 
       b b_alias, 
       c c_alias, 
       COUNT(DISTINCT d) d_alias
  FROM T1
 GROUP BY a, b, c;

However, a dependent child materialization could be created to support the value for COUNT(DISTINCT d):

-- child materialization, dependent subview
--There will be one row for each DISTINCT value of d

SELECT a a_alias, 
       b b_alias, 
       c c_alias, 
       count(*) d_alias_cnt
  FROM T1
 GROUP BY a, b, c, d;

The original view could then be rewritten as:

SELECT a a_alias, 
       b b_alias, 
       c c_alias, …

Scalable, Highly Available RADIUS solution using FreeRADIUS and MySQL Cluster

Before a client can start to access and consume services on a network, they must first be Authenticated to the network and then Authorized to use the services they are entitled too.  Their consumption of network resources then needs to be captured via the Accounting processes.  Collectively, Authentication, Authorization and Accounting (AAA) is a cornerstone of today’s network security, management and in many cases, monetization. RADIUS is a standard protocol to implement this AAA service.

As these networks grow, limitations can occur which add administrative overhead, inhibit flexible scaling and impact the timely synchronization of data across the AAA environment.

Using MySQL Cluster as the data store for a RADIUS server makes …

Funding for Aptana and Jolicloud. Ingres targets MySQL. Trent Reznor on Open Core (sort of). And more.

Follow 451 CAOS Links live @caostheory on Twitter and Identi.ca
“Tracking the open source news wires, so you don’t have to.”

Funding
# Aptana raised $7.8m in funding from Rembrandt Venture Partners and Accel Partners.

# Jolicloud raised $4.2m in series A funding for a Linux-based Netbook OS.

Not with a bang…
# Sun reported preliminary revenues for Q4 2009 of $2.58bn to $2.68bn, compared to $3.78bn a year ago.

Best of the rest
# Ingres …

The subject says it. I will be giving a free german language webinar on the MySQL Connector/C++ today at 15:00 local time. Registration is still open. The headline says it is specifically for OEM users. I don’t agree. The webinar is a good overview presentation on the product suitable for any MySQL developer developing applications with C++ .

Due to vacation season we have not released Connector/C++ 1.0.6 yet. Both Andrey and I have huge amounts of accured vacation from MySQL times - the time when MySQL was still an independent company. The 24th of August has been scheduled as a build date for 1.0.6. If you check the …

The subject says it. I will be giving a free german language webinar on the MySQL Connector/C++ today at 15:00 local time. Registration is still open. The headline says it is specifically for OEM users. I don’t agree. The webinar is a good overview presentation on the product suitable for any MySQL developer developing applications with C++ .

Due to vacation season we have not released Connector/C++ 1.0.6 yet. Both Andrey and I have huge amounts of accured vacation from MySQL times - the time when MySQL was still an independent company. The 24th of August has been scheduled as a build date for 1.0.6. If you check the …

For the last weeks, I have been writing a tool called "Incline," a program that automatically maintains consistency between sharded MySQL databases.  The aim of the software is to free application developers from hand-writing code for keeping consistency between RDB nodes, so that they can concentrate on writing the application logic.

Background

Denormalization is unavoidable in a sharded RDB environment.  For example, when a message is sent from a user to another user, the information should be stored on a database node where the sender of the message belongs to, and on another node where the receiver does.  In most cases, denormalization logic is hand-written by web application developers, and since it has been a burden for creating large-scale web services.  Incline takes off the load from developers.  By reading the definition files, Incline keeps the tables on a sharded MySQL …