15. A computer system, comprising: a processor; and hardware logic for: storing a current version of a store having a tokenized version of each document in a corpus of documents, a delta store accumulating changes to the current version of the store, and previously generated global analysis computations, wherein the previously generated global analysis computations include an anchor text table, a rank table, and a duplicates table; building a new version of the index and outputting a raw anchor text table and a raw duplicates table by accessing the current version of the store, the delta store, and the previously generated global analysis computations; and generating new global analysis computations by accessing the raw anchor text table, the raw duplicates table, and the previously generated global analysis computations, wherein the new global analysis computations include a new anchor text table, a new rank table, and a new duplicates table.
15. A computer system, comprising: a processor; and hardware logic for: storing a current version of a store having a tokenized version of each document in a corpus of documents, a delta store accumulating changes to the current version of the store, and previously generated global analysis computations, wherein the previously generated global analysis computations include an anchor text table, a rank table, and a duplicates table; building a new version of the index and outputting a raw anchor text table and a raw duplicates table by accessing the current version of the store, the delta store, and the previously generated global analysis computations; and generating new global analysis computations by accessing the raw anchor text table, the raw duplicates table, and the previously generated global analysis computations, wherein the new global analysis computations include a new anchor text table, a new rank table, and a new duplicates table. 16. The computer system of claim 15 , wherein the logic for index creation further comprises: building a new version of a delta store using the previously generated global analysis computations, a current version of a delta store, and newly crawled documents.