Title
AS-Index: A Structure for String Search Using n-Grams and Algebraic Signatures.
Abstract
We present the AS-Index, a new index structure for exact string search in disk resident databases. AS-indexrelies on a classical inverted file structure, its main innovation being a probabilistic search based on the properties of algebraicsignatures used both for n-grams hashing and pattern search. Specifically, the properties of our signatures allow to carry outa search by inspecting only two of the posting lists. The algorithm thus enjoys the unique feature of requiring a constantnumber of disk accesses, independently from both the pattern size and the database size. We conduct extensive experimentson large datasets to evaluate our index behavior. They confirm that it steadily provides a search performance proportionalto the two disk accesses necessary to obtain the posting lists. This makes our structure a choice of interest for the class ofapplications that require very fast lookups in large textual databases.We describe the index structure, our use of algebraic signatures and the search algorithm. We discuss the operationaltrade-offs based on the parameters that affect the behavior of our structure, and present the theoretical and experimentalperformance analysis. We next compare the AS-Index to the state-of-the-art alternatives and show that (i) the constructiontime matches that of the competitors, due to the similarity of structures, (ii) the search time constantly outperforms thestandard approach, thanks to the economical access to data complemented by signature calculations, which is at the core ofour search method.
Year
DOI
Venue
2016
10.1007/s11390-016-1618-6
J. Comput. Sci. Technol.
Keywords
Field
DocType
full text indexing, large-scale indexing, algebraic signature
Inverted index,String searching algorithm,Search algorithm,Computer science,Algorithm,Theoretical computer science,Hash function,Jump search,Probabilistic logic,Data access,Pattern search
Journal
Volume
Issue
ISSN
31
1
1860-4749
Citations 
PageRank 
References 
1
0.37
7
Authors
5
Name
Order
Citations
PageRank
Camélia Constantin194.87
Cédric du Mouza210014.67
Witold Litwin31937928.21
Philippe Rigaux4444110.71
Thomas Schwarz520919.12