Exploiting single-threaded model in multi-core in-memory systems

Chang Yao, Divyakant Agrawal, Gang Chen, Qian Lin, Beng Chin Ooi, Weng Fai Wong, Meihui Zhang

Research output: Contribution to journalArticle

9 Citations (Scopus)


The widely adopted single-threaded OLTP model assigns a single thread to each static partition of the database for processing transactions in a partition. This simplifies concurrency control while retaining parallelism. However, it suffers performance loss arising from skewed workloads as well as transactions that span multiple partitions. In this paper, we present a dynamic single-threaded in-memory OLTP system, called LADS, that extends the simplicity of the single-threaded model. The key innovation in LADS is the separation of dependency resolution and execution into two non-overlapping phases for batches of transactions. After the first phase of dependency resolution, the record actions of the transactions are partitioned and ordered. Each independent partition is then executed sequentially by a single thread, avoiding the need for locking. By careful mapping of the tasks to be performed to threads, LADS is able to achieve a high degree of balanced parallelism. We evaluate LADS against H-Store, a partition-based database; DORA, a data-oriented transaction processing system; and SILO, a multi-core in-memory OLTP engine. The experimental study shows that LADS achieves up to 20x higher throughput than existing systems and exhibits better robustness with various workloads.

Original languageEnglish
Article number7486988
Pages (from-to)2635-2650
Number of pages16
JournalIEEE Transactions on Knowledge and Data Engineering
Issue number10
Publication statusPublished - 1 Oct 2016
Externally publishedYes



  • concurrency control
  • in-memory OLTP system
  • multi-core
  • single-threaded model
  • Transaction management

ASJC Scopus subject areas

  • Information Systems
  • Computer Science Applications
  • Computational Theory and Mathematics

Cite this

Yao, C., Agrawal, D., Chen, G., Lin, Q., Ooi, B. C., Wong, W. F., & Zhang, M. (2016). Exploiting single-threaded model in multi-core in-memory systems. IEEE Transactions on Knowledge and Data Engineering, 28(10), 2635-2650. [7486988]. https://doi.org/10.1109/TKDE.2016.2578319