{
  "slug": "hot-cold-data-separation",
  "term": "Hot/cold data separation",
  "aliases": [
    "update-frequency data separation"
  ],
  "definition": "A flash-placement strategy that groups data by update frequency so frequently overwritten pages and long-lived pages need not share the same cleaning pool.",
  "note": "Hot and cold refer to update frequency, not physical temperature or hot/cold storage tiers. Spare-space allocation between pools matters alongside classification and block selection.",
  "related": [
    "greedy-garbage-collection",
    "garbage-collection",
    "over-provisioning",
    "ftl"
  ],
  "limitations": [
    {
      "text": "Data classification can change with workload; a placement model is not evidence that every controller implements it.",
      "citationIds": [
        "desnoyers"
      ]
    }
  ],
  "citations": [
    {
      "id": "desnoyers",
      "title": "Peter Desnoyers. Analytic Modeling of SSD Write Performance. SYSTOR 2012, sections 2-6, Tables 1-2. DOI: 10.1145/2367589.2367603.",
      "url": "https://www.ccs.neu.edu/home/pjd/papers/pjd-systor12.pdf",
      "accessed": "2026-10-11"
    },
    {
      "id": "hesela-op",
      "title": "Hesela: SSD over-provisioning, capacity denominators and analytical-model limits",
      "url": "https://hesela.com/analyses/ssd-overprovisioning-denominators/",
      "accessed": "2026-10-11"
    }
  ],
  "status": "shipping",
  "advantages": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-12"
}