Data Visualization with ElasticSearch and Protovis
This is a great article on ElasticSearch and visualization with Protovis but I mention it because of the following:
Nevertheless, a modern full-text search engine can do much more than that. At its core lies the inverted index, a highly optimized data structure for efficient lookup of documents matching the query. But it also allows to compute complex aggregations of our data, called facets. (Emphasis and links in original)
Do you think of facets as aggregations of data?
Is merging an aggregation of data?