{
  "status": "shipping",
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-17",
  "slug": "parquet-column-chunk",
  "term": "Parquet column chunk",
  "aliases": [
    "column chunk (Parquet)"
  ],
  "definition": "A Parquet column chunk is a contiguous sequence of encoded pages for one column within one row group.",
  "note": "Layout: a chunk belongs to a row group, not to all rows of the file. File metadata locates the chunks a reader needs; a column's chunks across multiple row groups are distinct. [parquet-format]\n\nPages: a chunk may contain multiple data pages and an optional dictionary page. Encoding, compression and optional page checksums operate below the chunk level; a chunk is not necessarily one page or one checksum. [parquet-chunks] [parquet-crc]\n\nCoverage: reading one column does not establish integrity of an excluded column. Hesela's experiment verifies selected values but does not measure physical reads or prefetch. [hesela-parquet]",
  "related": [
    "parquet",
    "parquet-row-group",
    "parquet-page-checksum"
  ],
  "citations": [
    {
      "id": "parquet-format",
      "title": "Apache Parquet: file layout and metadata",
      "url": "https://parquet.apache.org/docs/file-format/",
      "accessed": "2026-10-17"
    },
    {
      "id": "parquet-chunks",
      "title": "Apache Parquet: column chunks and page organization",
      "url": "https://parquet.apache.org/docs/file-format/data-pages/columnchunks/",
      "accessed": "2026-10-17"
    },
    {
      "id": "parquet-crc",
      "title": "Apache Parquet: page checksumming",
      "url": "https://parquet.apache.org/docs/file-format/data-pages/checksumming/",
      "accessed": "2026-10-17"
    },
    {
      "id": "hesela-parquet",
      "title": "Hesela: Parquet checksum and read-coverage experiment",
      "url": "https://hesela.com/analyses/parquet-checksums-read-coverage/",
      "accessed": "2026-10-17"
    }
  ],
  "advantages": [],
  "limitations": []
}