{
  "slug": "telescoping-adaptive-filter",
  "term": "Telescoping adaptive filter",
  "aliases": [
    "TAF",
    "Telescoping filter"
  ],
  "definition": "A telescoping adaptive filter is a quotient-filter-based membership structure that changes hash-selected remainders after detecting false positives.",
  "note": "Mechanism: instead of lengthening a fingerprint prefix, TAF advances a selector to another remainder from the stored key's hash. Selectors share compressed block storage rather than receiving a fixed bit budget per key. [taf-paper]\n\nBoundary: the remote representation needed for correction is excluded from filter-space accounting. Overflow resets a block's selectors and can forget earlier corrections. The theoretical space bound depends on the distinct-query horizon and hashing assumptions; it is not an unlimited-lifetime guarantee. [taf-paper]",
  "citations": [
    {
      "id": "taf-paper",
      "title": "Lee, McCauley, Singh and Stein. Telescoping Filter: A Practical Adaptive Filter. ESA 2021, sections 2.2-4. DOI: 10.4230/LIPIcs.ESA.2021.60.",
      "url": "https://drops.dagstuhl.de/storage/00lipics/lipics-vol204-esa2021/LIPIcs.ESA.2021.60/LIPIcs.ESA.2021.60.pdf",
      "accessed": "2026-11-10"
    },
    {
      "id": "hesela-adaptive",
      "title": "Hesela: adaptive-filter guarantees and correction-state limits",
      "url": "https://hesela.com/analyses/bloom-filters-lsm-read-cost/#adaptive-guarantees",
      "accessed": "2026-11-10"
    }
  ],
  "related": [
    "quotient-filter",
    "adaptive-quotient-filter",
    "cuckoo-filter"
  ],
  "status": "research",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-11-10",
  "provenance": [
    "Source synthesis of the ESA 2021 design; no throughput or false-positive measurements performed by Hesela."
  ]
}