CS377: Database Design - Aggregation with NoSQL

Activity Goals

The goals of this activity are:
  1. To define functions to aggregate values in a MongoDB data store

The Activity


Consider the activity models and answer the questions provided. First reflect on these questions on your own briefly, before discussing and comparing your thoughts with your group. Appoint one member of your group to discuss your findings with the class, and the rest of the group should help that member prepare their response. Answer each question individually from the activity on the Class Activity Questions discussion board. After class, think about the questions in the reflective prompt and respond to those individually in your notebook. Report out on areas of disagreement or items for which you and your group identified alternative approaches. Write down and report out questions you encountered along the way for group discussion.

Model 1: Aggregation Methods


  1. Investigate how to limit to two results on a find, but to make those results the second and third documents from the sorted result set.

Model 2: Quantitative Aggregation Methods


  1. By specifying an _id of _id, each item is individually counted in the average. Suppose asmttype is a key in your document; what do you think using that key as the _id of the aggregation does to the group? Try it to find out!


Submit your answers to the questions using the Class Activity Questions discussion board. You may also respond to questions or comments made by others, or ask follow-up questions there. Answer any reflective prompt questions in the Reflective Journal section of your OneNote Classroom personal section.