1. A computer-implemented method of querying multifaceted information in an information retrieval system, comprising: constructing, by said information retrieval (IR) system, an inverted index having a plurality of unique indexed tokens associated with a plurality of posting lists in a one-to-one correspondence, each posting list including one or more documents of a plurality of documents, wherein an indexed token of said plurality of unique indexed tokens is one of a facet token included as an annotation in a document of said plurality of documents and a path prefix of said facet token, wherein said annotation indicates a path within a tree structure representing a facet that includes said document, said tree structure including a plurality of nodes representing a category and one or more sub-categories that categorize said document; receiving, by said IR system, a query that includes a plurality of constraints on said plurality of documents, said plurality of constraints being associated with multiple indexed tokens of said plurality of unique indexed tokens and multiple posting lists corresponding to said multiple indexed tokens; and executing said query by said IR system, said executing including: identifying said multiple posting lists via a utilization of said plurality of constraints and said inverted index, and intersecting said multiple posting lists to obtain a result of said query.