FLIXR: Embedding Index Into Flash Translation Layer in SSDs

Gunjae Koo, Yunho Oh, Hung Wei Tseng, Won Woo Ro, Murali Annavaram

Research output: Contribution to journalArticlepeer-review


Flash memory technologies rely on flash translation layer (FTL) to manage no in-place update and garbage collection. Current FTL management schemes do not exploit the semantics of the accessed data. In this paper, we explore how semantic knowledge can be exploited to build and maintain indexes for stored data automatically. Data indexing is a critical enabler to accelerate many database applications and big data analytics. Unlike traditional per-table or per-file indexes that are managed separately from the data, we propose to maintain indexes on a per-flash page basis. Our approach, called FLash IndeXeR (FLIXR), builds and maintains page-level indexes whenever a page is written into the flash. FLIXR updates the indexes alongside any data updates at page granularity. The cost of the index update is hidden in the page write delays. FLIXR stores index data for each page within the FTL entry associated with that page, thereby piggybacking index access on a page access request. FLIXR accesses the index data in each FTL entry to determine whether the associated page stores data with a given key. FLIXR achieves 52.6% performance improvement for TPC-C and TPC-H benchmarks, compared to the conventional host-side indexing mechanism.

Original languageEnglish
Pages (from-to)250-263
Number of pages14
JournalIEEE Transactions on Computers
Issue number1
Publication statusPublished - 2023 Jan 1

Bibliographical note

Funding Information:
This work was supported in part by Defense Advanced Research Projects Agency (DARPA) under Grant HR001117C0053, in part by NSF under Grants 1719074 and 1940048, in part by Samsung under Grant 079856, and in part by the National Research Foundation of Korea (NRF) grants funded by the Korea Government (MSIT) under Grants NRF-2021R1C1C1012172, NRF-2021R1G1A1094978, NRF-2021R1A2B5B01002932

Publisher Copyright:
© 1968-2012 IEEE.

All Science Journal Classification (ASJC) codes

  • Software
  • Theoretical Computer Science
  • Hardware and Architecture
  • Computational Theory and Mathematics


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