Kegel, LarsHartmann, ClaudioThiele, MaikLehner, Wolfgang2022-01-272022-01-2720212021http://dx.doi.org/10.1007/s13222-021-00389-5https://dl.gi.de/handle/20.500.12116/38051Processing and analyzing time series datasets have become a central issue in many domains requiring data management systems to support time series as a native data type. A core access primitive of time series is matching, which requires efficient algorithms on-top of appropriate representations like the symbolic aggregate approximation (SAX) representing the current state of the art. This technique reduces a time series to a low-dimensional space by segmenting it and discretizing each segment into a small symbolic alphabet. Unfortunately, SAX ignores the deterministic behavior of time series such as cyclical repeating patterns or a trend component affecting all segments, which may lead to a sub-optimal representation accuracy. We therefore introduce a novel season- and a trend-aware symbolic approximation and demonstrate an improved representation accuracy without increasing the memory footprint. Most importantly, our techniques also enable a more efficient time series matching by providing a match up to three orders of magnitude faster than SAX.PAASAXTime series analysisTime series databasesText/Journal Article10.1007/s13222-021-00389-51610-1995