When moving from two data nodes to a bigger Cluster it is not necessarily true that you will have better performance. In fact you can get worse.

Here are some things to think about:

• Database Load (traffic to Cluster) - if you can handle query load X on a two node cluster and move the same load X to a four data node cluster you will likely get new_load_X=0.8X, i.e., a performance degradation. This has to do with 1) buffers are not filled up fast enough so the data nodes will do "timeout" based sending or 2) that the access patterns aren't scaling. To correct 1) you need to increase the load on the cluster so that internal communication buffers fill up faster.
  

Access pattern related "problems":

• For primary key operations (reads, updates, deletes) you will always go to the correct node to fetch the data with PK operations, no matter how many nodes you have. So no …

Configurator and Sandbox scripts are updated to use 7.0.9b.

You are recommended to upgrade!

Upgrade can be performend using these scripts:
Binary distribution - Upgrade script from 7.0.* -> 7.0.9b is here.
Source distribution - Upgrade script from 7.0.* -> 7.0.9b is here.

1. Copy the scripts to "install/"
2. chmod u+x upgrade-script.sh
   
3. ./upgrade-script.sh

After step 3) you need to run either:

• download-binary.sh
• download-and-compile.sh

and then

I read the article SQL is dead, Long live SQL and I have to say I really liked it. It spoke about the NoSQL movement and how relational database appeal to analysts.

This struck a cord with me. I always believed that what the regular applications play a small part (perhaps a very small part) of what happens to the data through out its lifetime.
After the data is inputted for the first time, it is analyzed, dissected, made sense of and placed in several reports and KPIs that are called for several times a day/week/month.

The business that paid for the application to be developed needs that data. It is not trivial to them at all. In fact, they may possibly make long term strategic decisions based on that data (in an ideal world). Hopefully, they use that data to improve how they react with their customers and the outside world, making …

In the article ‘Versioning MySQL data‘, I showed the basics of implementing a revisioning system using trigger. As Jens Schauder already pointed out, often the data of a record is spread across multiple tables, like an invoice with multiple invoice lines. Having each invoice line versioned individually isn’t really useful. Instead we want a new revision of the whole invoice on each change.

The perfect solution
Ideally a change of one or more parts of the invoice would be changed, a new revision would be created. There are several issues in actually creating this those. Detecting the change of multiple parts of the invoice at once, generating a single revision, would mean we need to know if the actions are done within the same transaction. Unfortunately there is a connection_id(), but no transaction_id() function in …

Another video from the recent OpenSQLCamp in Portland, Oregon….Earlier today I uploaded the Lightning Talk Videos. Due to the holiday I am unsure when the rest of the videos will be ready. When they are, I will do one blog post featuring them all.

However, I have had several requests for this specific video, so here is Brian Aker speaking about Drizzle.

The slides are up at http://www.slideshare.net/brianaker/drizzle-opensql-camp, and here’s the video:

(Note, I will not do a post for each video…..but since this one is up and ready, I figured I’d do it before I leave for the holiday).

I had an opportunity to catch up with Mark Atwood last week to discuss his new role at Gear6 and some of the interesting developments currently going on around memcached, including Gearman integration and its suitability for cloud computing environments.

Continuing the series on selecting records holding group-wise maximums.

The approach shown in the previous article is quite efficient, however, it can only be relied upon if the column being maximized is unique.

If the column is not unique (even along with the grouping column), the ties are possible: multiple records can satisfy the condition of holding a group-wise maximum.

In this article, I’ll show how to resolve the ties.

Let’s recreate the table we used in the previous article:

Table creation details

CREATE TABLE filler (
        id INT NOT NULL PRIMARY KEY AUTO_INCREMENT
) ENGINE=Memory;

CREATE TABLE t_distinct (
      id INT NOT NULL PRIMARY KEY,
      orderer INT NOT …

If you use MySQL Cluster or think that you might want to use it in the future (especially if you’ve thought ”if only they’d add that feature then it would be ideal for my application”) then now’s your chance to influence the product roadmap.

All you have to do is follow this link to the MySQL Cluster Community Survey and give your input.

Please also mention this to anyone you know of who might have an interest in MySQL Cluster.

Thanks in advance for you help.

Note: Wrote the talk in five minutes, fifty minutes before I gave it.
Second Note: I maintain No-SQL solutions, they have a place in this world (beyond just being a punchline).

OpenSQLCamp was a huge success! Not many folks have blogged about what they learned there….if you missed it, all is not lost. We did take videos of most of the sessions (we only had 3 video cameras, and 4 rooms, and 2 sessions were not recorded).

All the videos have been processed, and I am working on uploading them to YouTube and filling in details for the video descriptions. Not all the videos are up right now….right now all the lightning talks are up.

• 
  
• All the lightning talks belowin one continuous video (just over 54 minutes total)
  
• The Graph Engine (Antony Curtis)
  
• …