Comments on: Cassandra and Ruby: A Love Affair? (Key-Value Stores Part 3)

By: Cris from Credit Repair

Cris from Credit Repair — Wed, 20 Apr 2011 04:29:00 +0000

I’m just learning databases in a class that I’m taking at the moment. Good information although at this point it is a bit above my head.

By: 網站設計

網站設計 — Mon, 17 Jan 2011 21:01:37 +0000

Very interesting. thank you for sharing!

By: Erez

Erez — Sat, 06 Mar 2010 19:06:03 +0000

I am on Windows 7 – is there a way to get the cassandra gem?
Running "gem install cassandra" from command line console the command fails as it attempts to run nmake.

Thanks,
Erez

By: Stephan Schmidt

Stephan Schmidt — Wed, 16 Sep 2009 09:40:50 +0000

MongoDB is more like a SQL database e.g. MySQL. Replication is master/slave and possibly master/master in the future, similar to MySQL (also goes for sharding). MongoDB supports rich querying compared to other schemaless, document stores. The main difference to classic models (SQL) is that MongoDB is schemaless.

Cassandra is a distributed storage. This scales much longer than "classic" replication. The downside: Cassandra has not as rich query capabilities.

Cheers
Stephan
http://www.codemonkeyism.com

By: Rhett

Rhett — Wed, 02 Sep 2009 23:22:08 +0000

Java Preferences is the Apple-supported way to go. If you're using Java Preferences, you also want to set your JAVA_HOME like so:

export JAVA_HOME=`/usr/libexec/java_home`

(note the backticks). Also, if you use Java Preferences to pick your JDK, you don't have to modify your PATH. More info:

http://lists.apple.com/archives/java-dev/2009/Jun…

By: Michael Sheakoski

Michael Sheakoski — Tue, 01 Sep 2009 02:38:41 +0000

FYI if you search for Java Preferences in Spotlight, you can pick which version it will load first. In Snow Leopard I only see Java SE 6 so it shouldn't be an issue.

By: joevandyk

joevandyk — Mon, 31 Aug 2009 22:03:33 +0000

From mongo's website: "Mongo does not support full master-master replication. However, for certain restricted use cases master-master can be used. Generally, we recommend one does not use the database in a master-master mode."

That's a bit different than what Cassandra offers, isn't it?

By: dm_10gen

dm_10gen — Mon, 31 Aug 2009 21:22:15 +0000

In mongodb you can do any query. If one of the terms of the query is the partition key, the query will be executed on the smallest possible set of shards. If the query is general it will go to all shards and collect the results.

MongoDB sharding is currently in alpha (the core database is full production now).

By: User

User — Mon, 31 Aug 2009 21:05:11 +0000

Last I looked MongoDB didn't actually support partitioned queries except by pkey; hopefully this has changed.

By: Kirk Haines

Kirk Haines — Mon, 31 Aug 2009 17:52:56 +0000

Hi. I'm going to be doing a MongoDB article in a few weeks, so I can better address the comparison between the two of them there, and I am making a note to focus on that comparison as part of the article. I haven't had enough time really putting MongoDB through its paces to give a good, objective comparison just yet, though, and I don't want to throw out my vauge impressions at this point because I may well change my mind.