scholarly journals CoroBase

2020 ◽  
Vol 14 (3) ◽  
pp. 431-444
Author(s):  
Yongjun He ◽  
Jiacheng Lu ◽  
Tianzheng Wang

Data stalls are a major overhead in main-memory database engines due to the use of pointer-rich data structures. Lightweight coroutines ease the implementation of software prefetching to hide data stalls by overlapping computation and asynchronous data prefetching. Prior solutions, however, mainly focused on (1) individual components and operations and (2) intra-transaction batching that requires interface changes, breaking backward compatibility. It was not clear how they apply to a full database engine and how much end-to-end benefit they bring under various workloads. This paper presents CoroBase, a main-memory database engine that tackles these challenges with a new coroutine-to-transaction paradigm. Coroutine-to-transaction models transactions as coroutines and thus enables inter-transaction batching, avoiding application changes but retaining the benefits of prefetching. We show that on a 48-core server, CoroBase can perform close to 2x better for read-intensive workloads and remain competitive for workloads that inherently do not benefit from software prefetching.

2010 ◽  
Vol 40-41 ◽  
pp. 206-211
Author(s):  
Zhi Lin Zhu

One approach to achieving high performance in the DBMS in the critical application is to store the database in main memory rather than on disk. One can then design new data structures and algorithms oriented towards increasing the efficiency of the main memory database -MMDB. In this paper we present some results on index structures from an ongoing study of MMDB. We propose a new index structure, the T-tail Tree. We give the main algorithm of the T-tail Tree and the performance of these algorithms. Our results indicate that T-tail Tree provides good overall performance in main memory.


Author(s):  
Huazhuang Yao ◽  
Yongyan Wang ◽  
Shuai Wang ◽  
Kun Li ◽  
Chao Guo

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jeongmin Bae ◽  
Hajin Jeon ◽  
Min-Soo Kim

Abstract Background Design of valid high-quality primers is essential for qPCR experiments. MRPrimer is a powerful pipeline based on MapReduce that combines both primer design for target sequences and homology tests on off-target sequences. It takes an entire sequence DB as input and returns all feasible and valid primer pairs existing in the DB. Due to the effectiveness of primers designed by MRPrimer in qPCR analysis, it has been widely used for developing many online design tools and building primer databases. However, the computational speed of MRPrimer is too slow to deal with the sizes of sequence DBs growing exponentially and thus must be improved. Results We develop a fast GPU-based pipeline for primer design (GPrimer) that takes the same input and returns the same output with MRPrimer. MRPrimer consists of a total of seven MapReduce steps, among which two steps are very time-consuming. GPrimer significantly improves the speed of those two steps by exploiting the computational power of GPUs. In particular, it designs data structures for coalesced memory access in GPU and workload balancing among GPU threads and copies the data structures between main memory and GPU memory in a streaming fashion. For human RefSeq DB, GPrimer achieves a speedup of 57 times for the entire steps and a speedup of 557 times for the most time-consuming step using a single machine of 4 GPUs, compared with MRPrimer running on a cluster of six machines. Conclusions We propose a GPU-based pipeline for primer design that takes an entire sequence DB as input and returns all feasible and valid primer pairs existing in the DB at once without an additional step using BLAST-like tools. The software is available at https://github.com/qhtjrmin/GPrimer.git.


2012 ◽  
Vol 28 (4) ◽  
pp. 559-568 ◽  
Author(s):  
Min-Hsiung Hung ◽  
Wen-Huang Tsai ◽  
Haw-Ching Yang ◽  
Yi-Jhong Kao ◽  
Fan-Tien Cheng

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