{
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-12",
  "slug": "monotonic-reads",
  "term": "Monotonic reads",
  "aliases": [
    "Monotonic-read consistency"
  ],
  "definition": "Monotonic reads is a session guarantee requiring successive reads to observe states that include the effects of writes relevant to the session's earlier reads.",
  "note": "Changing replicas must not make the session lose previously observed write effects. Values themselves need not increase numerically: a later valid update may decrease a counter. Monotonic reads does not alone require the freshest global state or visibility of the session's own writes that have not yet been read; read-your-writes is a separate guarantee.",
  "related": [
    "linearizability",
    "read-your-writes"
  ],
  "citations": [
    {
      "id": "session-guarantees",
      "title": "Douglas B. Terry et al. Session Guarantees for Weakly Consistent Replicated Data. PDIS 1994, sections 3.1 and 3.2.",
      "url": "https://classes.cs.uchicago.edu/archive/2026/spring/23380-1/papers/terry_sessionguarantees.pdf",
      "accessed": "2026-10-12"
    },
    {
      "id": "hesela-consistency",
      "title": "Storage consistency: ordering is not a transaction or a durability promise",
      "url": "https://hesela.com/analyses/storage-consistency-ordering/",
      "accessed": "2026-10-12"
    }
  ]
}