Skip to main content
v2026.11,772 entries · CC-BY 4.0
Dictionary termTrack BProposedv2026.2

Data lake

A storage repository that holds large volumes of structured, semi-structured, and unstructured data in their native formats, deferring schema-on-write requirements so that data can be ingested cheaply and only structured at the time of read or analysis.

ByCASRAI Editorial Board
· Last updated 23 Aug 2026
Share this

Ask CASRAI · included with Regulatory Radar

Ask about Data lake

Ask CASRAI answers research-administration questions and cites the passages behind every claim — and says so when the corpus does not cover something, instead of guessing. It comes with a Regulatory Radar subscription at $29 a month, alongside the daily digest of regulatory changes and the dashboard of what changed.

150 questions a day, on this site, over the API, or inside your own tools through the CASRAI MCP server.

Everything CASRAI publishes — this page, the dictionary, the guides and the news — stays free to read, with no account and no card.

Examples

Worked examples

  • Is an instance

    An institutional research-IT data lake holding raw genomics FASTQ files, microscopy images, and instrument logs.

  • Is an instance

    An astronomical observatory's S3-based data lake ingesting raw telescope outputs prior to pipeline processing.

Counter-examples

Looks similar, but isn't

  • Not an instance

    A small structured database is not a data lake.

  • Not an instance

    A curated, schema-on-write data warehouse is the contrasting pattern, not a data lake.

Editorial commentary

A data lake is a general information-systems pattern for storing large volumes of raw data in its native format — structured, semi-structured, or unstructured — without imposing a fixed schema at write time, deferring structure until a consumer actually queries the data (‘schema-on-read’). The pattern emerged in the early 2010s, notably promoted by James Dixon at Pentaho, as a counter-position to traditional data warehousing’s schema-on-write approach. Modern data lakes are typically built on cloud object storage (S3, Azure Blob, GCS), with optional table-format layers (Apache Iceberg, Delta Lake, Hudi) adding transactional and schema-management features on top, and compute engines such as Spark or Trino querying the stored data directly.

Scope note: data-lake architecture is a large, well-established data-engineering discipline with its own extensive literature — table-format internals, partitioning strategy, and query-engine tuning are best learned from that literature directly, not from a research-standards page. This entry stays narrow to why the term shows up in a research-administration or research-data-management context at all.

Where data lakes show up in research infrastructure

In research-data contexts, data lakes are typically used as a landing zone for raw, high-volume observational data — instrument telemetry, sensor logs, sequencing output — before it is curated, quality-controlled, and structured into a research-facing product. This is a deliberately earlier, rougher stage than a trusted digital repository‘s curated holdings, and a different architectural pattern from a data hub: a hub applies its harmonised model up front (schema-on-write) to serve a specific consuming community, where a lake defers structure and stores data close to its raw upstream form — see the data hub entry’s own comparison section for the fuller distinction. A data warehouse sits at the opposite end from a lake on the same schema-on-write axis, typically for structured institutional reporting rather than raw research data.

References

  • Dixon J., ‘Pentaho, Hadoop, and Data Lakes’ (Pentaho blog, 2010).
  • Russom P., ‘Data Lakes: Purposes, Practices, Patterns, and Platforms’ (TDWI Best Practices Report, 2017).

Machine-readable encodings

Use in your systems

JATS XML <role> element
xml
<role vocab="credit"
      vocab-identifier="https://casrai.org/dictionary/"
      vocab-term="Data lake"
      vocab-term-identifier="https://casrai.org/dictionary/term/data-lake" />
Schema.org DefinedTerm (JSON-LD)
json
{
  "@context": "https://schema.org",
  "@type": "DefinedTerm",
  "@id": "https://casrai.org/dictionary/term/data-lake",
  "name": "Data lake",
  "identifier": "https://casrai.org/dictionary/term/data-lake",
  "description": "A storage repository that holds large volumes of structured, semi-structured, and unstructured data in their native formats, deferring schema-on-write requirements so that data can be ingested cheaply and only structured at the time of read or analysis.",
  "inDefinedTermSet": "https://casrai.org/dictionary/domain/data-infrastructure#set",
  "url": "https://casrai.org/dictionary/term/data-lake",
  "sameAs": [],
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "publisher": {
    "@id": "https://casrai.org/#organization"
  },
  "author": {
    "@id": "https://casrai.org/#editorial-team"
  },
  "datePublished": "2026-05-21T02:17:58",
  "dateModified": "2026-08-23T04:44:37",
  "inLanguage": "en-GB",
  "isAccessibleForFree": true
}

Referenced across the research world

University of Cambridge logoColumbia University logoCrossref logoUniversity of Edinburgh logoHarvard University logoUniversity of Oxford logoPrinceton University logoStanford School of Medicine logoUniversity College London logoORCID logoUniversity of Cambridge logoColumbia University logoCrossref logoUniversity of Edinburgh logoHarvard University logoUniversity of Oxford logoPrinceton University logoStanford School of Medicine logoUniversity College London logoORCID logo
  • University of Cambridge logo
  • Columbia University logo
  • Crossref logo
  • University of Edinburgh logo
  • Harvard University logo
  • University of Oxford logo
  • Princeton University logo
  • Stanford School of Medicine logo
  • University College London logo
  • ORCID logo

View CASRAI adoption →

Regulatory Radar

Stop finding out after the fact

$29/month, cancel anytime. Daily digest updates from our analysis, a dashboard holding the same items, and a cited assistant for everything they raise.

  • Federal Register, Federal Register+, Grants.gov, Regulations.gov, NSF News, UKRI, plus CASRAI’s own published content.
  • 72,264 indexed passages, and every answer cites the ones it drew on.