On Nonlinear Learned String Indexing

On Hardness of Several String Indexing Problems

Let D = {d1, d2, ..., dD} be a collection of D string documents of n characters in total. The two-pattern matching problems ask to index D for answering the following queries efficiently. – report/count the unique documents containing P1 and P2. – report/count the unique documents containing P1, but not P2. Here P1 and P2 represent input patterns of length p1 and p2 respectively. Linear space d...

Indexing for String Queries using

We present ve index trees designed for supporting string searches. We discuss Counted Trees, Substring Trees, and Regular Expression Trees, all of which suuer the same problem { their attempts at approximating a large set of data lead to an almost complete lack of information in the interior nodes. A variant of B-Trees, called a Preex-Suux Tree, avoids this diiculty by severely restricting the ...

Lessons Learned From Indexing Close Word Pairs

We describe experiments with proximity-aware ranking functions that use indexing of word pairs. Our goal is to evaluate a method of “mild” pruning of proximity information, which would be appropriate for a moderately loaded retrieval system, e.g., an enterprise search engine. We create an index that includes occurrences of close word pairs, where one of the words is frequent. This allows one to...

Home Photo Indexing using Learned Visual Keywords

Indexing Methods for Approximate String Matching

Indexing for approximate text searching is a novel problem receiving much attention because of its applications in signal processing, computational biology and text retrieval, to name a few. We classify most indexing methods in a taxonomy that helps understand their essential features. We show that the existing methods, rather than completely diierent as they are regarded, form a range of solut...