TY  - JOUR
A1  - Richly, Keven
A1  - Schlosser, Rainer
A1  - Boissier, Martin
T1  - Budget-conscious fine-grained configuration optimization for spatio-temporal applications
JF  - Proceedings of the VLDB Endowment
N2  - Based on the performance requirements of modern spatio-temporal data mining applications, in-memory database systems are often used to store and process the data. To efficiently utilize the scarce DRAM capacities, modern database systems support various tuning possibilities to reduce the memory footprint (e.g., data compression) or increase performance (e.g., additional indexes). However, the selection of cost and performance balancing configurations is challenging due to the vast number of possible setups consisting of mutually dependent individual decisions. In this paper, we introduce a novel approach to jointly optimize the compression, sorting, indexing, and tiering configuration for spatio-temporal workloads. Further, we consider horizontal data partitioning, which enables the independent application of different tuning options on a fine-grained level. We propose different linear programming (LP) models addressing cost dependencies at different levels of accuracy to compute optimized tuning configurations for a given workload and memory budgets. To yield maintainable and robust configurations, we extend our LP-based approach to incorporate reconfiguration costs as well as a worst-case optimization for potential workload scenarios. Further, we demonstrate on a real-world dataset that our models allow to significantly reduce the memory footprint with equal performance or increase the performance with equal memory size compared to existing tuning heuristics.
KW  - General Earth and Planetary Sciences
KW  - Water Science and Technology
KW  - Geography, Planning and Development
Y1  - 2022
U6  - https://doi.org/10.14778/3565838.3565858
SN  - 2150-8097
VL  - 15
IS  - 13
SP  - 4079
EP  - 4092
PB  - Association for Computing Machinery (ACM)
CY  - [New York]
ER  - 
TY  - JOUR
A1  - Boissier, Martin
T1  - Robust and budget-constrained encoding configurations for in-memory database systems
JF  - Proceedings of the VLDB Endowment
N2  - Data encoding has been applied to database systems for decades as it mitigates bandwidth bottlenecks and reduces storage requirements. But even in the presence of these advantages, most in-memory database systems use data encoding only conservatively as the negative impact on runtime performance can be severe. Real-world systems with large parts being infrequently accessed and cost efficiency constraints in cloud environments require solutions that automatically and efficiently select encoding techniques, including heavy-weight compression. In this paper, we introduce workload-driven approaches to automaticaly determine memory budget-constrained encoding configurations using greedy heuristics and linear programming. We show for TPC-H, TPC-DS, and the Join Order Benchmark that optimized encoding configurations can reduce the main memory footprint significantly without a loss in runtime performance over state-of-the-art dictionary encoding. To yield robust selections, we extend the linear programming-based approach to incorporate query runtime constraints and mitigate unexpected performance regressions.
KW  - General Earth and Planetary Sciences
KW  - Water Science and Technology
KW  - Geography, Planning and Development
Y1  - 2021
U6  - https://doi.org/10.14778/3503585.3503588
SN  - 2150-8097
VL  - 15
IS  - 4
SP  - 780
EP  - 793
PB  - Association for Computing Machinery (ACM)
CY  - [New York]
ER  -