{
  "schemaVersion": 1,
  "experiment": "parquet-integrity-boundaries",
  "evidenceType": "measured-api-behavior",
  "generatedAt": "2026-10-17T19:09:34.743874+00:00",
  "sourceSha256": "2c442b6681f860c700b0ce44d877190c77a78a87f7568428d2db753c3b8edde8",
  "requirementsSha256": "0bbd7856f6ec73eebf6f4e98df031a4ac802d738d12735cceaa113b00ab48c19",
  "environment": {
    "python": "3.12.3",
    "pyarrow": "21.0.0",
    "arrowCpp": "21.0.0",
    "kernel": "6.8.0-146-generic",
    "system": "Linux",
    "machine": "x86_64"
  },
  "repetitions": 3,
  "casesPerRepetition": 9,
  "inputs": {
    "rows": 128,
    "rowGroupRows": 64,
    "columns": [
      "id",
      "measurement"
    ],
    "type": "required INT64",
    "compression": "NONE",
    "dictionary": false,
    "dataPageVersion": "1.0",
    "fileVersion": "2.6",
    "synthetic": true
  },
  "method": "Write two deterministic fixtures with/without page CRC, flip one payload bit in copies, compare nine read scopes/settings against complete expected selected values; repeat on fresh temporary files.",
  "limits": "Controlled synthetic one-bit fault on one host and pinned library; not field corruption frequency, power-loss testing, a storage benchmark, hostile-tampering assessment or exhaustive file validation. No compressed, encrypted, nested or dictionary pages tested. Projection and row-group cases compare only selected data.",
  "runs": [
    {
      "faults": {
        "checksumPresent": {
          "byteOffset": 791,
          "column": "measurement",
          "rowGroup": 0,
          "rowIndex": 17,
          "xorMask": 1,
          "beforeValue": 100017,
          "afterValue": 100016,
          "fileBytes": 3077,
          "originalSha256": "1693db533cc88b7eacf13693ce704318c074d928105f518204a9a90bfb17bffa",
          "modifiedSha256": "7ba5b90d5bf964b82148f162da8350a74eb24d380f9d28b86cc2142291202285"
        },
        "checksumAbsent": {
          "byteOffset": 780,
          "column": "measurement",
          "rowGroup": 0,
          "rowIndex": 17,
          "xorMask": 1,
          "beforeValue": 100017,
          "afterValue": 100016,
          "fileBytes": 3054,
          "originalSha256": "9591ac4f7a627bf069a711b1e294f90b95e4fe7e1cc73e3488c34c0c597e0505",
          "modifiedSha256": "4bbb17771cb39fc4db2df2ee4955879f65c6ed2b4703bac4e575a4a2ea37807f"
        }
      },
      "observations": [
        {
          "case": "clean-checked",
          "verification": true,
          "scope": "all-data",
          "outcome": "matches-selected-data",
          "rows": 128,
          "mismatchCount": 0,
          "mismatches": []
        },
        {
          "case": "corrupt-default",
          "verification": "default",
          "scope": "all-data",
          "outcome": "wrong-values",
          "rows": 128,
          "mismatchCount": 1,
          "mismatches": [
            {
              "column": "measurement",
              "rowWithinResult": 17,
              "expected": 100017,
              "actual": 100016
            }
          ]
        },
        {
          "case": "corrupt-check-off",
          "verification": false,
          "scope": "all-data",
          "outcome": "wrong-values",
          "rows": 128,
          "mismatchCount": 1,
          "mismatches": [
            {
              "column": "measurement",
              "rowWithinResult": 17,
              "expected": 100017,
              "actual": 100016
            }
          ]
        },
        {
          "case": "corrupt-check-on",
          "verification": true,
          "scope": "all-data",
          "outcome": "checksum-error",
          "rows": null,
          "mismatchCount": null,
          "errorType": "OSError",
          "error": "could not verify page integrity, CRC checksum verification failed for page_ordinal 0"
        },
        {
          "case": "projection-check-on",
          "verification": true,
          "scope": "id-only",
          "outcome": "matches-selected-data",
          "rows": 128,
          "mismatchCount": 0,
          "mismatches": []
        },
        {
          "case": "other-group-check-on",
          "verification": true,
          "scope": "row-group-1",
          "outcome": "matches-selected-data",
          "rows": 64,
          "mismatchCount": 0,
          "mismatches": []
        },
        {
          "case": "metadata-only",
          "verification": "not-applicable",
          "scope": "metadata",
          "outcome": "metadata-readable",
          "rows": 128,
          "rowGroups": 2,
          "mismatchCount": null
        },
        {
          "case": "absent-crc-check-on",
          "verification": true,
          "scope": "all-data",
          "outcome": "wrong-values",
          "rows": 128,
          "mismatchCount": 1,
          "mismatches": [
            {
              "column": "measurement",
              "rowWithinResult": 17,
              "expected": 100017,
              "actual": 100016
            }
          ]
        },
        {
          "case": "clean-no-crc-check-on",
          "verification": true,
          "scope": "all-data",
          "outcome": "matches-selected-data",
          "rows": 128,
          "mismatchCount": 0,
          "mismatches": []
        }
      ]
    },
    {
      "faults": {
        "checksumPresent": {
          "byteOffset": 791,
          "column": "measurement",
          "rowGroup": 0,
          "rowIndex": 17,
          "xorMask": 1,
          "beforeValue": 100017,
          "afterValue": 100016,
          "fileBytes": 3077,
          "originalSha256": "1693db533cc88b7eacf13693ce704318c074d928105f518204a9a90bfb17bffa",
          "modifiedSha256": "7ba5b90d5bf964b82148f162da8350a74eb24d380f9d28b86cc2142291202285"
        },
        "checksumAbsent": {
          "byteOffset": 780,
          "column": "measurement",
          "rowGroup": 0,
          "rowIndex": 17,
          "xorMask": 1,
          "beforeValue": 100017,
          "afterValue": 100016,
          "fileBytes": 3054,
          "originalSha256": "9591ac4f7a627bf069a711b1e294f90b95e4fe7e1cc73e3488c34c0c597e0505",
          "modifiedSha256": "4bbb17771cb39fc4db2df2ee4955879f65c6ed2b4703bac4e575a4a2ea37807f"
        }
      },
      "observations": [
        {
          "case": "clean-checked",
          "verification": true,
          "scope": "all-data",
          "outcome": "matches-selected-data",
          "rows": 128,
          "mismatchCount": 0,
          "mismatches": []
        },
        {
          "case": "corrupt-default",
          "verification": "default",
          "scope": "all-data",
          "outcome": "wrong-values",
          "rows": 128,
          "mismatchCount": 1,
          "mismatches": [
            {
              "column": "measurement",
              "rowWithinResult": 17,
              "expected": 100017,
              "actual": 100016
            }
          ]
        },
        {
          "case": "corrupt-check-off",
          "verification": false,
          "scope": "all-data",
          "outcome": "wrong-values",
          "rows": 128,
          "mismatchCount": 1,
          "mismatches": [
            {
              "column": "measurement",
              "rowWithinResult": 17,
              "expected": 100017,
              "actual": 100016
            }
          ]
        },
        {
          "case": "corrupt-check-on",
          "verification": true,
          "scope": "all-data",
          "outcome": "checksum-error",
          "rows": null,
          "mismatchCount": null,
          "errorType": "OSError",
          "error": "could not verify page integrity, CRC checksum verification failed for page_ordinal 0"
        },
        {
          "case": "projection-check-on",
          "verification": true,
          "scope": "id-only",
          "outcome": "matches-selected-data",
          "rows": 128,
          "mismatchCount": 0,
          "mismatches": []
        },
        {
          "case": "other-group-check-on",
          "verification": true,
          "scope": "row-group-1",
          "outcome": "matches-selected-data",
          "rows": 64,
          "mismatchCount": 0,
          "mismatches": []
        },
        {
          "case": "metadata-only",
          "verification": "not-applicable",
          "scope": "metadata",
          "outcome": "metadata-readable",
          "rows": 128,
          "rowGroups": 2,
          "mismatchCount": null
        },
        {
          "case": "absent-crc-check-on",
          "verification": true,
          "scope": "all-data",
          "outcome": "wrong-values",
          "rows": 128,
          "mismatchCount": 1,
          "mismatches": [
            {
              "column": "measurement",
              "rowWithinResult": 17,
              "expected": 100017,
              "actual": 100016
            }
          ]
        },
        {
          "case": "clean-no-crc-check-on",
          "verification": true,
          "scope": "all-data",
          "outcome": "matches-selected-data",
          "rows": 128,
          "mismatchCount": 0,
          "mismatches": []
        }
      ]
    },
    {
      "faults": {
        "checksumPresent": {
          "byteOffset": 791,
          "column": "measurement",
          "rowGroup": 0,
          "rowIndex": 17,
          "xorMask": 1,
          "beforeValue": 100017,
          "afterValue": 100016,
          "fileBytes": 3077,
          "originalSha256": "1693db533cc88b7eacf13693ce704318c074d928105f518204a9a90bfb17bffa",
          "modifiedSha256": "7ba5b90d5bf964b82148f162da8350a74eb24d380f9d28b86cc2142291202285"
        },
        "checksumAbsent": {
          "byteOffset": 780,
          "column": "measurement",
          "rowGroup": 0,
          "rowIndex": 17,
          "xorMask": 1,
          "beforeValue": 100017,
          "afterValue": 100016,
          "fileBytes": 3054,
          "originalSha256": "9591ac4f7a627bf069a711b1e294f90b95e4fe7e1cc73e3488c34c0c597e0505",
          "modifiedSha256": "4bbb17771cb39fc4db2df2ee4955879f65c6ed2b4703bac4e575a4a2ea37807f"
        }
      },
      "observations": [
        {
          "case": "clean-checked",
          "verification": true,
          "scope": "all-data",
          "outcome": "matches-selected-data",
          "rows": 128,
          "mismatchCount": 0,
          "mismatches": []
        },
        {
          "case": "corrupt-default",
          "verification": "default",
          "scope": "all-data",
          "outcome": "wrong-values",
          "rows": 128,
          "mismatchCount": 1,
          "mismatches": [
            {
              "column": "measurement",
              "rowWithinResult": 17,
              "expected": 100017,
              "actual": 100016
            }
          ]
        },
        {
          "case": "corrupt-check-off",
          "verification": false,
          "scope": "all-data",
          "outcome": "wrong-values",
          "rows": 128,
          "mismatchCount": 1,
          "mismatches": [
            {
              "column": "measurement",
              "rowWithinResult": 17,
              "expected": 100017,
              "actual": 100016
            }
          ]
        },
        {
          "case": "corrupt-check-on",
          "verification": true,
          "scope": "all-data",
          "outcome": "checksum-error",
          "rows": null,
          "mismatchCount": null,
          "errorType": "OSError",
          "error": "could not verify page integrity, CRC checksum verification failed for page_ordinal 0"
        },
        {
          "case": "projection-check-on",
          "verification": true,
          "scope": "id-only",
          "outcome": "matches-selected-data",
          "rows": 128,
          "mismatchCount": 0,
          "mismatches": []
        },
        {
          "case": "other-group-check-on",
          "verification": true,
          "scope": "row-group-1",
          "outcome": "matches-selected-data",
          "rows": 64,
          "mismatchCount": 0,
          "mismatches": []
        },
        {
          "case": "metadata-only",
          "verification": "not-applicable",
          "scope": "metadata",
          "outcome": "metadata-readable",
          "rows": 128,
          "rowGroups": 2,
          "mismatchCount": null
        },
        {
          "case": "absent-crc-check-on",
          "verification": true,
          "scope": "all-data",
          "outcome": "wrong-values",
          "rows": 128,
          "mismatchCount": 1,
          "mismatches": [
            {
              "column": "measurement",
              "rowWithinResult": 17,
              "expected": 100017,
              "actual": 100016
            }
          ]
        },
        {
          "case": "clean-no-crc-check-on",
          "verification": true,
          "scope": "all-data",
          "outcome": "matches-selected-data",
          "rows": 128,
          "mismatchCount": 0,
          "mismatches": []
        }
      ]
    }
  ]
}