Abstract. The Permuterm index [Garfield 1976] is a time-efficient and elegant solution to the string dictionary problem in which pattern queries may possibly include one wild-card symbol (called Tolerant Retrieval problem). Unfortunately the Permuterm index is space inefficient because it quadruples the dictionary size ...

Does Permuterm index require Postfiltering?

k-gram index is more space-efficient permuterm index does not require postfiltering.

What are K-gram indexes?

A k-gram index maps a k-gram to a postings list of all possible vocabulary terms that contain it. ... It is noteworthy that the postings list is sorted alphabetically. Spelling Correction. While creating the candidate list of possible corrected words, we can use the “k-gram overlap” to find the most likely corrections.