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For the latest on Oracle’s acquisition of MySQL via Sun, see Everything you always wanted to know about MySQL but were afraid to ask

# Yahoo! Open! Sourced! Traffic! Server!

# Red Hat launched Enterprise Virtualization for Servers for managing Linux and Microsoft Windows servers.

# 10gen, the company behind MongoDB, has …

I have been asked a number of times "do you think there is a need for a column oriented database in the open source world?"

The answer has been yes!

Users and vendors have asked me this question a number of times. The problem has been most of the vendors were interested in creating closed source solutions around either Drizzle/MySQL, or, did their efforts in a way that made serious modifications to the backend (aka... made poor use of the storage engine interface).

For these reasons I have not really found myself all that thrilled to work with what has been out there. Also, I would often find that the commitment to open source was either luke warm or "we will do it, once we have some traction...".

My response to that? "Tell me more when you open source it. I'll see if it will work."

For this reason I was very happy to see Calpont do their release of …

InnoDB uses a 16kb page by default. I want to know whether performance improves with an 8kb database page for my workload. Two servers were setup to run a mirror of the production database workload. One used 8kb InnoDB pages and the other used 16kb.

It isn't clear that my performance will improve with 8kb pages. But my results are a function of my workload and data. I expect that 8kb pages will be much better for others. For example, when your data access pattern is uniform and most data is fetched by primary key, then smaller pages can be better as less space is wasted in the buffer pool per active row. However, a smaller page size will also waste more space from fragmentation for LOB columns. Peak IOPs on spinning disk are similar for 8kb pages and 16kb pages with random IO bound workloads. But when using flash, peak IOPs for 8kb pages are much higher than 16kb pages. So you, or your consultant, have interesting work to do if you want to …

Today I’m proud to announce the first public release of our ActiveRecord database connection magic plugin: DbCharmer.

DB Charmer – ActiveRecord Connection Magic Plugin

DbCharmer is a simple yet powerful plugin for ActiveRecord that does a few things:

1. Allows you to easily manage AR models’ connections (switch_connection_to method)
2. Allows you to switch AR models’ default connections to a separate servers/databases
3. Allows you to easily choose where your query should go (on_* methods family)
4. Allows you to automatically send read queries to your slaves while masters would handle all the updates.
5. Adds multiple databases migrations to ActiveRecord

Installation

There are two options when …

Last night I was asked about index cardinality. One of the members of the North Texas MySQL Users Group was using phpMyadmin and noticed an element marked 'cardinality' and asked me what it meant. And I will admit I was stumped.

The manual says:

ANALYZE TABLE determines index cardinality (as displayed in the Cardinality column of SHOW INDEX output) by doing ten random dives to each of the index trees and updating index cardinality estimates accordingly. Because these are only estimates, repeated runs of ANALYZE TABLE may produce different numbers. This makes ANALYZE TABLE fast on InnoDB tables but not 100% accurate because it does not take all rows into account.

MySQL uses …

MySQL Cluster 6.3.28 and 7.0.9 introduce the MySQL server option --ndb-wait-setup. This makes sure that clients can not connect the SQL Node when no Data Nodes are available within, by default, 15 seconds. When the timeout is reached, and no Data Nodes are available, the NDB storage engine will be marked as unavailable.

The following will appear in the MySQL server error log when --ndb-wait-setup=30 has been set:

 [Note] NDB: NodeID is 10, management server …

MySQL Cluster Performance Tuning Best Practices

Are you experiencing current performance bottlenecks in your high availability applications ? Are you designing a new mission-critical application and want to know how best to structure your schema and index strategy for optimal performance? Interested in how to transform your SQL into faster, more efficient queries?

Then this free web presentation is for you! You will get expert insight and learn best practices to help you identify those areas of database and application design that will give you the greatest benefits for performance when using MySQL Cluster.

We will discuss guidelines and best practices covering the following areas:

• General Design Concepts and Guidelines
• Schema Optimization
  • BLOB/Text vs VARBINARY/VARCHAR
  • Partition by Key
• Index Selection and Tuning
…

Only a few weeks after Walter’s session on Multi-Master Replication with MMM and thanks to the great gang at MySQL Docs (my colleagues from long ago!) I’ll be doing a MySQL University session in a few days, about the GRAPH computation engine. From talks/demos I’ve done about it so far, I’ve learnt that people love it but there are lots of interesting questions. After all, it’s a pretty new and in a way exotic thing.

MySQL University uses DimDim, an online presentation service. You’ll see slides, and hear my voice. You can also type questions in a live chat room. We actually even got desktop sharing working so a live demo is possible, we’ll see how that goes on the day (I’ll make sure to have static slides for the same also

For session details and the exact link to DimDim, see the …

Having produced a nice little series of 124 patches (yes, really), I recently had to find out what patch introduced a problem for distcheck to pass. Since distcheck takes quite some time to execute, I want to make as few runs as possible.

In Git, there is the bisect command that can be used to perform bisection testing of a series of patches, but quilt does not have anything like that, so to simplify my job, I needed to implement that for quilt.

I started by defining a shell function that did the actual test, and returned the result.

do_test () {
    echo -n "running distcheck..."
    make -j6 distcheck >/dev/null 2>&1
}

After that, I added code to add values for some variables used and to process options to the script. The script supports two options: --lower and …

This Thursday (November 5th, 10:00 UTC - note the different time for this session!), Arjen Lentz of Open Query will present the brand new GRAPH computation engine for MySQL.

From the abstract: Most of us have had to deal with hierarchies (trees) and graphs (such as friend-of-a-friend style problems), and have thus learn that this is -at best- a bit of a monster to do in an SQL/RDBMS. Until now. The GRAPH engine (GPLv2 licensed) is a MySQL storage engine allowing hierarchies and more complex graph structures to be handled in a relational fashion. In a nutshell, tree structures and friend-of-a-friend style searches can now be done using standard SQL syntax, and results joined onto other tables. http://openquery.com/graph

For MySQL University sessions, point your …