{
  "slug": "lazybase",
  "term": "LazyBase",
  "aliases": [],
  "definition": "LazyBase is a research database that batches updates while letting read queries trade result freshness for query cost.",
  "note": "The EuroSys 2012 prototype applies self-consistent updates (SCUs) atomically and gives each query a consistent snapshot. An old snapshot need not mix parts of an atomic batch. Updates supply replacement values; the service does not support general read-modify-write transactions. [lazybase-2012]\n\nQueries read the merged authority plus pipeline batches needed for their freshness requirement. Sorted batches have indexes; unsorted batches require scans. Relaxing freshness can avoid those scans, without promising a fixed speedup. [lazybase-2012]\n\nThe FAST 2014 production design uses independent filesystem-segment batches and disables client-requested freshness in the early product. FreshnessComplete marks the boundary before which every segment's events have been observed; FreshnessPartial marks the latest event processed anywhere. Coverage between them is incomplete, so the upper timestamp is not a completeness watermark for incremental backup. [express-query-2014]\n\nThat design also removed auto-increment ID remapping because it could destroy pathname sort locality, require joins and scans, and serialize ingestion. [express-query-2014]\n\nIllustration: with completeness at 10:00 and the latest event at 10:05, another segment's 10:03 event may still be absent. Advancing a backup cursor to 10:05 can skip it. This example is constructed, not a measurement.",
  "status": "research",
  "advantages": [],
  "limitations": [],
  "related": [
    "snapshot-isolation",
    "monotonic-reads",
    "replication-lag",
    "pbs-k-staleness"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "citations": [
    {
      "id": "lazybase-2012",
      "title": "Cipar et al. LazyBase: Trading Freshness for Performance in a Scalable Database. EuroSys 2012, 169-182, sections 3-4. DOI: 10.1145/2168836.2168854.",
      "url": "https://istc-cc.cmu.edu/publications/papers/2012/euro166-cipar.pdf",
      "accessed": "2026-11-11"
    },
    {
      "id": "express-query-2014",
      "title": "Johnson et al. From Research to Practice: Engineering a Production Metadata Database for a Scale Out File System. FAST 2014, 191-198, sections 3.1-3.3.",
      "url": "https://www.usenix.org/conference/fast14/technical-sessions/presentation/johnson",
      "accessed": "2026-11-11"
    },
    {
      "id": "hesela-consistency",
      "title": "Hesela: Storage consistency, ordering, transactions and durability.",
      "url": "https://hesela.com/analyses/storage-consistency-ordering/",
      "accessed": "2026-11-11"
    }
  ],
  "updated": "2026-11-11",
  "provenance": [
    "Source synthesis of the research prototype and a separate historical production design, not a benchmark reproduction or a claim of current product availability.",
    "The FAST 2014 system is StoreAll Express Query. The EuroSys 2012 evaluation uses tweets and synthetic data on its stated hardware/Cassandra configuration; the reported comparisons do not establish performance against current releases. [lazybase-2012] [express-query-2014]"
  ]
}