{
  "slug": "vt-tree",
  "term": "VT-tree",
  "aliases": [
    "Variable-Transmission tree"
  ],
  "definition": "A VT-tree extends an LSM-tree with stitching that reuses eligible nonoverlapping block spans during merging.",
  "note": "Stitching builds a new index over retained spans and rewritten overlap. A minimum span length trades fewer copies for scan locality; retained blocks beside rewritten data can leave holes requiring cleaning. [vt-paper]\n\nThe design uses quotient filters so merging membership metadata need not reread skipped keys. This is a filter-maintenance constraint, not only a false-positive-rate choice. [vt-paper]",
  "citations": [
    {
      "id": "vt-paper",
      "title": "Shetty et al. Building Workload-Independent Storage with VT-Trees. FAST 2013, pp. 17-30, section 3.1.",
      "url": "https://www.usenix.org/system/files/conference/fast13/fast13-final165_0.pdf",
      "accessed": "2026-11-10"
    },
    {
      "id": "hesela-stitching",
      "title": "Hesela: VT-tree stitching and filter-maintenance costs",
      "url": "https://hesela.com/analyses/bloom-filters-lsm-read-cost/#vt-stitching",
      "accessed": "2026-11-10"
    }
  ],
  "related": [
    "lsm-tree",
    "compaction",
    "quotient-filter"
  ],
  "status": "research",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-11-10",
  "provenance": [
    "FAST 2013 research design. Source synthesis, not a modern implementation benchmark or replication."
  ]
}