Index Structures for Fast Similarity Search for Real Vectors. II*

Abstract

This survey article considers index structures for fast similarity search for objects represented by real-valued vectors. Structures for both exact and faster but approximate similarity search are considered. Index structures based on partitioning into regions (including hierarchical ones) and on proximity graphs are mainly presented. The acceleration of similarity search using the transformation of initial data is also discussed. The ideas of concrete algorithms including recently proposed ones are outlined. The approaches to the acceleration of similarity search in index structures of the considered types and also on the basis of similarity-preserving hashing are discussed and compared.