David's Tech Blog

Full text search in noSQL databases is far less common than one would think. Most apps I build can benefit from full text searches, even if they don’t need sophisticated search capabilities. There are external solutions for most databases, mostly tying in Lucene through Elastic Search or Solr. Sometimes those external solutions are just the way you need to go, and I’ve used external Lucene integration with CouchDb before. But I was glad when I saw that text searches are included in MongoDb 2.4, at least at a beta stage.

The main catch I’ve had in my testing so far is I had a hard time figuring out how to enable this feature. Like many people (I expect), I’m using packages for Ubuntu, so I needed to figure out how to get this feature enabled in /etc/mongodb.conf. The documentation shows how to enable text searches in the command to start mongo, and mentions that you can put this in the config file, but it doesn’t tell you how to put it in the config file.

This doesn’t work:
textSearchEnabled=true

You end up with a response that says
error command line: unknown option textSearchEnabled

This is the syntax to put in the config file instead:
setParameter=textSearchEnabled=true

Once I added that, the feature was enabled. In the mongodb console I was then able to add my initial index like this:
db.content.ensureIndex( { title:'text', body: 'text' });

and search it like this:
db.content.runCommand("text", {search:'Lorem'})

This returns an object that contains an array called results with the results in it, one result object for each document that matched the text in either the title or body field. Each result is in turn an object with a score and the matching document. It also returns a stats object that tells how many documents were found and how long it took.

Overall, this feature is very promising. While it doesn’t appear as strong in its search capabilities as the Lucene solutions, having it directly available in MongoDb itself is a big win for deploying solutions for customers quickly.

Next up: interacting with the text search functionality through the native node.js driver.