Index Data Structure for Fast Subset and Superset Queries

Abstract

Abstract.A new data structure set-trie for storing and retrieving sets is proposed. Efficient manipulation of sets is vital in a number of systems including datamining tools, object-relational database systems, and rule-based expert systems. Data structure set-trie provides efficient algorithms for set containment operations. It allows fast access to subsets and supersets of a given parameter set. The performance of operations is analyzed empirically in a series of experiments on real-world and artificial datasets. The analysis shows that sets can be accessed in O(c * |set|) time where |set| represents the size of parameter set and c is a constant.

Graph-based dynamic analysis: Efficient characterization of dynamic timing and activity distributions

“…Element indices are inserted into the SetTrie such that a traversal path from the root to a leaf corresponds to a set of elements that is stored in the SetTrie. For example, the SetTrie in Figure 2 The original SetTrie [15] allows for any internal node to also act as the last element in the set, by using a flag for each node. We do not need this feature, since UNITs require that we only insert a new set if a superset does not already exist in the SetTrie.…”

“…However, due to the exponential complexity of the getAllSubsets function [15], we use a different strategy. If a set is inserted successfully into the SetTrie, we store a copy of the set in a separate list.…”

“…If the check reveals no superset, we traverse down the tree while the path of traversal matches exactly with the set being inserted and create new nodes after the first point of deviation to accomodate the set being inserted. The exact algorithms for insert and existsSuperset can be found in [15].…”

“…We use a data structure called the SetTrie [15] to perform fast subset and superset operations. We briefly explain the data structure below.…”

Multiset Representation of Objects in Information Retrieval Systems

“…It is an extension of the set-trie data structure proposed by Savnik [6]. Set-trie is used for storing and fast retrieval of objects represented as sets and provides the nearest-neighbor search by implementing methods that perform set-containment queries.…”