1. A method comprising: determining to store a spatial document index for a corpus of documents, wherein the spatial document index indexes documents in the corpus according to spatial references found within the documents; determining to store a plurality of spatial keyword document indexes for the corpus of documents, wherein the spatial keyword document indexes are derived from the spatial document index, are for a different keyword, and indexes those documents among the corpus that are responsive to that keyword; and intersecting a portion of the spatial document index and selected indexes among the plurality of spatial keyword document indexes to identify a result set of those documents from among the corpus of documents that are responsive to a query.
1. A method comprising: determining to store a spatial document index for a corpus of documents, wherein the spatial document index indexes documents in the corpus according to spatial references found within the documents; determining to store a plurality of spatial keyword document indexes for the corpus of documents, wherein the spatial keyword document indexes are derived from the spatial document index, are for a different keyword, and indexes those documents among the corpus that are responsive to that keyword; and intersecting a portion of the spatial document index and selected indexes among the plurality of spatial keyword document indexes to identify a result set of those documents from among the corpus of documents that are responsive to a query. 11. The method of claim 1 , wherein the spatial document index and at least one of the spatial keyword document indexes comprise nodes within corresponding tree data structures, said method further comprising: identifying those indexes among the spatial keyword document indexes that are responsive to said one or more keywords, the identified indexes being said selected ones of the plurality of spatial keyword document indexes; and to generate said portion of the spatial document index, trimming away all nodes from the spatial document index that correspond to coordinates outside of a region bounded by the spatial information.