Dynamic partitioning of signature files

Abstract

The signature file access method has proved to be a convenient indexing technique, in particular for text data Because it can deal with unformatted data, many application domains have shown interest in signature file techniques, e.g., office information systems, statistical and logic databases. We argue that multimedia databases should also take advantage of this method, provided convenient storage structures for organizing signature tiles are available, Our main concern here is the dynamic organization of signatures based on a partitioning paradigm called Quick Filter. A signature file is partitioned by a hashing function and the partitions are orgamzed by linear hashing, Thorough performance evaluation of the new scheme is provided, and it is compared with single-level and multdevel storage structures Results show that quick filter is economical in space and very convenient for applications dealing with large files of dynamic data, and where user queries result in signatures with high weights. These characteristics are particularly interesting for multimedia databases, where integrated access to attributes, text and images must be provided.

A Signature-Based Indexing Method for Efficient Content-Based Retrieval of Relative Temporal Patterns

“…The signature key used is usually a substring of the signature. By partitioning the signatures, some of the partitions need not to be searched during the execution of a query so that the number of accesses can be reduced [26], [27], [28].…”

Signature-based structures for objects with set-valued attributes

“…Horizontal or vertical fragmentation in combination with hashing techniques were studied in [13][14][15]. A similar approach has been investigated by Zezula et al who proposed the method of quick filter [16]. In [17], the hybrid structure of parametric weighted filter (PWF) was introduced taking advantage of the hash-based partitioning methods.…”

“…In [17], the hybrid structure of parametric weighted filter (PWF) was introduced taking advantage of the hash-based partitioning methods. In this work, as in [16], hash buckets contain not only a single partition page but a specified number of pages with the aid of superimposition (''or-ing'').…”

“…In this paper, we focus on the advantages that could arise from the creation of a hybrid structure based on the advantages of hashing and the S-tree as well. In [16,17], the authors have introduced a similar hybrid structure, where the only clustering involved had as a measure of similarity a suffix of usually limited length, which played the role of a hash table key. Here, we try to increase the similarity of grouped signatures even more by using the similarity functions that are introduced in [20,21].…”

Improved Methods for Signature-Tree Construction

“…Horizontal or vertical fragmentation in combination with hashing techniques were studied in [14,15,16]. A similar approach has been investigated by Zezula et al, who proposed the method of Quick Filter [17,18].…”