{
  "slug": "cceh",
  "term": "Cacheline-Conscious Extendible Hashing",
  "aliases": [
    "CCEH"
  ],
  "definition": "CCEH is a persistent-memory hash index that groups cacheline-sized buckets into segments addressed through a directory.",
  "note": "Segments shrink the directory but enlarge the unit of splitting. Ordered metadata updates and directory recovery replace explicit logging in the paper's design. [cceh-paper]",
  "status": "research",
  "advantages": [],
  "limitations": [
    {
      "text": "The original evaluation emulates persistent memory with DRAM; lookup probing can access additional cachelines.",
      "citationIds": [
        "cceh-paper"
      ]
    },
    {
      "text": "Dash evaluates a modified CCEH implementation on Optane, including allocation and reclamation repairs.",
      "citationIds": [
        "dash-paper"
      ]
    }
  ],
  "related": [
    "persistent-memory",
    "fptree",
    "persistence-ordering"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-11-13",
  "citations": [
    {
      "id": "cceh-paper",
      "title": "Moohyeon Nam, Hokeun Cha, Young-ri Choi, Sam H. Noh and Beomseok Nam. Write-Optimized Dynamic Hashing for Persistent Memory. FAST 2019, pp. 31-44, sections 3-6.",
      "url": "https://www.usenix.org/system/files/fast19-nam.pdf",
      "accessed": "2026-11-13"
    },
    {
      "id": "dash-paper",
      "title": "Lu, Hao, Wang and Lo. Dash: Scalable Hashing on Persistent Memory. PVLDB 13(8), 2020, sections 1.1, 6.1-6.2. DOI: 10.14778/3389133.3389134.",
      "url": "https://www.vldb.org/pvldb/vol13/p1147-lu.pdf",
      "accessed": "2026-11-13"
    },
    {
      "id": "hesela-pmem",
      "title": "Hesela: CCEH lookup, split and recovery boundaries.",
      "url": "https://hesela.com/analyses/pmem-persistence-domains-dax/#cceh",
      "accessed": "2026-11-13"
    }
  ],
  "provenance": [
    "Primary-source review of FAST 2019 sections 3-6 and Dash sections 1.1, 6.1-6.2; no benchmark or crash-test reproduction. Historical implementation observations are not a claim about current repository defects."
  ]
}