Efficient Static and Dynamic In-Database Tensor Decompositions on Chunk-Based Array Stores

As the relevant data sets get large, existing in-memory schemes for tensor decomposition become increasingly ineffective and, instead, memory-independent solutions, such as in-database analytics, are necessitated. In this paper, we present techniques for efficient implementations of in-database tensor decompositions on chunk-based array data stores. The proposed static and incremental in-database tensor decomposition operators and their optimizations address the constraints imposed by the main memory limitations when handling large and high-order tensor data. Firstly, we discuss how to implement alternating least squares operations efficiently on a chunk-based data storage system. Secondly, we consider scenarios with frequent data updates and show that compressed matrix multiplication techniques can be effective in reducing the incremental tensor decomposition maintenance costs. To the best of our knowledge, this paper presents the first attempt to develop efficient and optimized in-database tensor decomposition operations. We evaluate the proposed algorithms on tensor data sets that do not fit into the available memory and results show that the proposed techniques significantly improve the scalability of this core data analysis.