Kristina Chodorow explains the MongoDB safe and fsync options:

safe and fsync are not the same, here’s a rundown of the options:

• safe => false: do not wait for a db response
• safe => true: wait for a db response
• safe => num: wait for that many servers to have the write before returning

• fsync => true: fsync the write to disk before returning. fsync => true implies safe=>true, but not visa versa.
• If fsync=>false and safe=>true and the write could be in successfully applied to a mmapped file but not yet written to disk.

Related to MongoDB durability.

Original title and link for this post: MongoDB safe and fsync Explained (published on the NoSQL blog: myNoSQL)

Andrew Glover:

Both MongoDB and CouchDB are document-oriented datastores. They both work with JSON documents. They both are usually thrown into the NoSQL bucket. They’re both hip. But that’s where the similarities, for the most part, stop.

When it comes to queries, both couldn’t be any more different.

They differ even in the implementation and behavior of MapReduce.

Original title and link for this post: CouchDB and MongoDB: Quering (published on the NoSQL blog: myNoSQL)

Posted on the MongoDB mailing list:

I have about 500M log file entries each representing an “ad impression” (we are an advertising company). Each “hit” has about 50 attributes to it (example: Country, State, City, Adsize, Browser, OS, etc) .. I want to load all 500M into some form of database and then run queries against this set.

As you could expect MongoDB is considered as a possibility. But I’d call that a biased vendor advise. I’ll be blunt: invest in your future by using Hadoop and Pig. Hive may fit too.

Original title and link for this post: MongoDB or Hadoop? (published on the NoSQL blog: myNoSQL)

Ishan Kumar, the creator of MongoVUE, a MongoDB GUI for Windows, interviewed about the future of the tool:

(Short term):

• Inline editing/updating
• GridFS support

(Long term):

• Support for Linux through Mono.
• An interactive shell like the one that comes with MongoDB.
• Data Visualizations – ability to fetch data not just as a series of documents but as interactive charts and models. Some preliminary work in this area will be available in the next release 0.3.1.
• Data Modeling and Schema design. Although MongoDB is schemaless, there is much value in having a documented schema model for collaboration and communication in team members.

Sounds like a lot of work, but definitely exciting features for MongoVUE and MongoDB users.

Original title and link for this post: MongoVUE: What’s on the Roadmap? (published on the NoSQL blog: myNoSQL)

Having used MongoDb almost exclusively with the NoRM C# driver for several months now, this is something that I have always wanted to do, just to satisfy my own curiosity.

Unfortunately “basic” is the wrong word. Just another useless benchmark.

Original title and link for this post: MongoDB and SQL Server Basic Speed Tests (published on the NoSQL blog: myNoSQL)

Couchio announced another user^[1] of CouchDB: the European Organization for Nuclear Research (CERN) — responsible for the Large Hadron Collider — in the Compact Muon Solenoid experiment:

The DMWM team has issues that don’t fit well into standard relational databases or files in a filesystem. Being able to easily access and consolidate data from distributed locations with minimal latency is required routinely. Typically, external access to a site is limited, so incoming connections to a database aren’t possible. The team often doesn’t have clear requirements to address, which means metadata is either not collected or not effectively used. Generally, the team members must prototype tools quickly and be able to demonstrate that they are ready to go into production.

In case you missed it, back in June, the same project ☞ announced the usage of MongoDB. So, wouldn’t it be interesting to hear why MongoDB was replaced by CouchDB? (in case that’s true and the two are not in fact used in parallel).

Update: according to @LusciousPear the two projects are used side-by-side.

Original title and link for this post: CouchDB Users: The Large Hadron Collider (published on the NoSQL blog: myNoSQL)

Mark Ramm talks on why they chose MongoDB for SourceForge, how it compared to other possible solutions, the problems encountered, how they fixed them, overall lessons learned, and answering questions

From the same InfoQ series:

• CouchDB at BBC presented by Enda Farrell
• Justin Sheehy interviewed about Building Blocks of Dynamo-like Distributed Systems
• Emil Eifrem about NoSQL and the Benefits of Graph Databases

Original title and link for this post: MongoDB at SourceForge (published on the NoSQL blog: myNoSQL)

Kristina Chodorow:

GUIs: We decided early on not to create a GUI for MongoDB and let the community sort one out, which has had mixed consequences: there are now over a dozen to choose from! (We’re still hoping it’ll settle down.) ^[1]

This doesn’t apply to MongoDB consulting, but I’m not sure about hosting where 10gen is not yet present.

Original title and link for this post: History of MongoDB (published on the NoSQL blog: myNoSQL)

A bit old, but cool way to get test data into MongoDB:

curl http://stream.twitter.com/1/statuses/sample.json -u<user>:<pass> | mongoimport -c twitter_live

Original title and link for this post: MongoDB: Twitter Stream as Input Data (published on the NoSQL blog: myNoSQL)