{
  "status": "shipping",
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-17",
  "slug": "parquet-row-group",
  "term": "Parquet row group",
  "aliases": [
    "row group (Parquet)"
  ],
  "definition": "A Parquet row group is a logical partition of rows represented by one column chunk for each column.",
  "note": "Layout: a row group is not a single row-major byte array; the format does not guarantee a physical structure for the group as a whole. Its column chunks contain the encoded pages. [parquet-concepts]\n\nSelection: PyArrow 21.0 can read a specified row group and selected columns from it. A successful selected-group read does not validate other groups; in Hesela's synthetic experiment the untouched group reads correctly despite a changed value elsewhere. [arrow-parquetfile] [hesela-parquet]",
  "related": [
    "parquet",
    "parquet-column-chunk",
    "parquet-page-checksum"
  ],
  "citations": [
    {
      "id": "parquet-concepts",
      "title": "Apache Parquet: row groups, column chunks and pages",
      "url": "https://parquet.apache.org/docs/concepts/",
      "accessed": "2026-10-17"
    },
    {
      "id": "arrow-parquetfile",
      "title": "Apache Arrow 21.0: ParquetFile row-group and column selection",
      "url": "https://arrow.apache.org/docs/21.0/python/generated/pyarrow.parquet.ParquetFile.html",
      "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": []
}