Abstract: The present invention relates to searching documents based on a range index. A range index may comprise range-searchable elements having explicit data types, such as integers, real numbers, geographic locations, dates, times, etc. The data type determines what operators can be used in expressions. Each element of the range index corresponds to an occurrence of an item in the document collection that satisfies the range expression. In addition, range indexes can be aggregated into a set of aggregate indexes to facilitate evaluation. Aggregation may depend on the field's type or the distribution of values. For example, date fields might have a range indexed by day, by month at one level, and then by year at another level. Thus, these new file structures and evaluation techniques result in a new inverted list structure that allows efficient query evaluation using expressions that operate on typed data.