AS-index: a structure for string search using n-grams and algebraic signatures

AS-Index is a new index structure for exact string search in disk resident databases. It uses hashing, unlike known alternate structures, tree or trie based, and indexes every n-gram in the database. supported as well. The hash function relies on the algebraic signatures of the n-grams. Use of hashing provides for constant index access time for arbitrarily long patterns, unlike other structures whose search cost is at best logarithmic. The storage overhead of AS-Index is basically 500 - 600%, similar to that of alternatives or smaller. We show the index structure, our use of algebraic signatures and the search algorithm. We present the theoretical and experimental performance analysis. We compare the AS-Index to main alternatives. We conclude that AS-Index is an attractive structure and we indicate directions for future work.

• Type: Conference
• Year: 2009
• Where: CIKM
• Authors: Cédric du Mouza, Witold Litwin, Philippe Rigaux, Thomas J. E. Schwarz
• Keywords: Algebraic Signatures, CIKM 2009, Database, Exact String Search, Index Structure