GPU-PLWAH: GPU-based implementation of the PLWAH algorithm for compressing bitmaps. (English) Zbl 1318.68078

Andrzejewski, Witold; Wrembel, Robert

Control Cybern. 40, No. 3, 627-650 (2011).

Summary: Bitmap indexes are data structures applied to indexing attributes in databases and data warehouses. A drawback of a bitmap index is that its size increases when the domain of an indexed attribute increases. As a consequence, for wide domains, the size of a bitmap index is too large to be efficiently processed. Hence, various techniques of compressing bitmap indexes have been proposed. A compression technique incurs some system overhead (mainly CPU) for compression and decompression operations. For this reason, we propose to use additional processing power of graphical processing units (GPUs). In this paper, we present the GPU-PLWAH algorithm that is a parallel implementation of the recently developed PLWAH compression algorithm. GPU-PLWAH was experimentally compared to its traditional CPU version as well as to our previously developed parallel GPU implementation of the WAH compression algorithm. The experiments show that applying GPUs significantly reduces compression/decompression time.

MSC:

68P30	Coding and information theory (compaction, compression, models of communication, encoding schemes, etc.) (aspects in computer science)
68P05	Data structures
68P15	Database theory
68P20	Information storage and retrieval of data

Keywords:

data warehouse; GPGPU; bitmap index; bitmap index compression; PLWAH; WAH

Software:

GPU-PLWAH; GPUTeraSort; CUDA