The latest from the MySQL community

Another thing I find interesting about MongoDB is its approach to Durability, Data Consistency and Availability. It is very relaxed and will not work for some applications but for others it can be usable in current form. Let me explain some concepts and compare it to technologies in MySQL space.

First I think MongoDB is best compared no to MySQL Server but MySQL Cluster, especially in newer versions which implement "sharding". Same as commit to NDB Storage engine does not normally mean commit to disk, but rather commit to network it does not mean commit to disk with MongoDB, furthermore MongoDB uses Asynchronous replication, meaning it may take some time before data will be at more than one node. You can also use getLastError() to ensure data is propagated to the slave. So you can see it as a hybrid between MySQL Cluster and innodb_flush_log_at_trx_commit=2 mode. The second difference of course the fact MongoDB is not crash safe - similar to …

I went to MongoSF today - quite an event, and I hope to have a chance to write more about it. This post is about one replication problem and how MongoDB solves it.

If you're using MySQL Replication when your master goes down it is possible for some writes to be executed on the master, but not on the slave, which gets promoted to the master. When Master comes back up it has some updates done to it which cause it to be inconsistent with data on the new Master. In MySQL world we can chose to either ignore this problem (or may be even replay those changes on slaves and hope it works out), re-clone it from the slave or use mk-table-checksum to find inconsistencies and re-sync them with mk-table-sync. Both of these operations can be very expensive for large databases.

MongoDB approach used …

I’m hearing a lot of “NoSQL” these days. To really understand how (and) does it works, I decided to give a try on MongoDB. MongoDB (hu*mongo*us) is an open source, scalable, high-performance, schema-free, document-oriented database written in the C++ programming language. MongoDB is not a Relational Database Management System. The database manages collections of JSON […]

Persistence Smoothie: Blending NoSQL and SQL – see user feedback and comments at http://joind.in/talk/view/1332.

Michael Bleigh from Intridea, high-end Ruby and Ruby on Rails consultants, build apps from start to finish, making it scalable. He’s written a lot of stuff, available at http://github.com/intridea. @mbleigh on twitter

NoSQL is a new way to think about persistence. Most NoSQL systems are not ACID compliant (Atomicity, Consistency, Isolation, Durability).

Generally, most NoSQL systems have:

• Denormalization
  
• Eventual Consistency
  
• Schema-Free
  
• Horizontal Scale
  

NoSQL tries to scale (more) simply, it is starting to go mainstream – NY …

Topics for this podcast:

*Jacobsen v. Katzer and open source impact
*Intel, Nokia team up for MeeGo open source OS
*Open source continues in embedded space
*MongoDB and the advent of the NoSQL databases
*Copyrights, complexities, control and conflict

iTunes or direct download (21:48, 6.07 MB)

Licensing, community, funding, revenue, business models, patents. And more.

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“Tracking the open source news wires, so you don’t have to.”

# The OpenOffice.org Community announced the release of OpenOffice.org 3.2.

# An interview with Michael Tiemann on licensing and community.

# DotNetNuke raised $8m series B funding.

# Microsoft updated its Linux Integrated Components, introducing support for RHEL in Hyper-V.

# An interview with Marten Mickos on …

The No-SQL tag really lumps together a lot of concepts that are in fact as distinct from eachother as they are from SQL/RDBMS.

An object store is not at all similar to Cassandra and Hypertable, which is not at all like an column store. And when looking at BigTable derivatives, it’s quite important to realise that Google actually does joins in middle layers or apps, so while BigTable does not have joins, the apps essentially do use them – I’ve heard it professed that denormalising everything might be a fab idea, but I don’t quite believe in that for all cases, just like I don’t believe in ditching the structured form of RDBMS being the solution.

SQL/RDBMS has had a few decades of dominance now, and has thus become the great “general purpose” tool. With the ascent of all the other tools, it’s definitely worthwhile to look at them, but also realise that each (inluding SQL based ones) have their place. Moving all your …

OpenSQLCamp was a huge success! I took videos of most of the sessions (we only had 3 video cameras, and 4 rooms, and 2 sessions were not recorded). Unfortunately, I was busy doing administrative stuff for opensqlcamp for the opening keynote and first 15 minutes of the session organizing, and when I got to the planning board, it was already full….so I was not able to give a session.

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• Comparing Non-Relational Databases: MongoDB, Tokyo Tyrant, CouchDB by Igal Koshevoy of Pragmaticraft

Yahoo! Open! Sources! Traffic! Server! Funding for 10gen. And more.

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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 …

The NoSQL event in New York had a number of presentations on non relational technologies including of Hadoop, MongoDB and CouchDB.

Coming historically from a relational background of 20 years with Ingres, Oracle and MySQL I have been moving my focus towards non relational data store. The most obvious and well used today is memcached, a non persistent distributed key/value pair store. There are a number of persistent key/value stores in the marketplace, Tokyo Cabinet, …