Monthly Archives: October 2010

Recommendation Engine Powered by Hadoop (Part 2)

In Part 1 of this post the focus was on finding the correlation between items, based on rating data available in individual items. The MR job output was the correlation coefficient matrix, with correlation coefficient  values between 0 and 1 … Continue reading

Posted in Collaborative Filtering, Data Mining, Hadoop and Map Reduce, Java | Tagged , , | 10 Comments

Recommendation Engine Powered by Hadoop (Part 1)

Personalized recommendations are ubiquitous in social network and shopping sites these days. How do they do it? Al long as enough user interaction data is available for items e.g., products in shopping sites, a kind of recommendation engine based on … Continue reading

Posted in Collaborative Filtering, Data Mining, Hadoop and Map Reduce | Tagged , , | 25 Comments

Cassandra secondary index to the rescue

In an earlier blog, I discussed Cassandra data model for a BPM system. I used an eCommerce order processing system driven by a BPM as an example. In this post, we will discuss some of the data access usage scenario … Continue reading

Posted in Cassandra, Indexing, NOSQL | Tagged , , , | 1 Comment