> ## Documentation Index
> Fetch the complete documentation index at: https://docs.openlayer.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Duplicate rows

> Learn how to use the duplicate rows test

## Definition

The duplicate rows test checks if there are rows that are identical to each other in the dataset.

## Taxonomy

* **Task types**: LLM, tabular classification, tabular regression, text classification.
* **Availability**: <Tooltip tip="Continuously evaluate your models and datasets as you iterate on their versions.">development</Tooltip>
  and <Tooltip tip="Monitor a model in production, measure its health, check for drifts and set up alerts.">monitoring</Tooltip>.

## Why it matters

* Duplicate rows on the training set can lead the model to overfit on the duplicated examples.
* Duplicate rows on the validation set can distort the [aggregate metrics](/tests/performance/aggregate-metrics#available-metrics), making them overly optimistic or pessimistic.

## Test configuration examples

If you are writing a `tests.json`, here are a few valid configurations for the character length test:

<CodeGroup>
  ```json Development theme={null}
  [
    {
      "name": "No duplicate rows",
      "description": "Asserts that there are no duplicate rows",
      "type": "integrity",
      "subtype": "duplicateRowCount",
      "thresholds": [
        {
          "insightName": "duplicateRowCount",
          "insightParameters": null,
          "measurement": "duplicateRowCount", // Using the absolute row count
          "operator": "<=",
          "value": 0 // integer
        }
      ],
      "subpopulationFilters": null,
      "mode": "development",
      "usesValidationDataset": true, // Apply test to the validation set
      "usesTrainingDataset": false,
      "usesMlModel": false,
      "syncId": "b4dee7dc-4f15-48ca-a282-63e2c04e0689" // Some unique id
    },
    {
      "name": "No duplicate rows",
      "description": "Asserts that there are no duplicate rows",
      "type": "integrity",
      "subtype": "duplicateRowCount",
      "thresholds": [
        {
          "insightName": "duplicateRowCount",
          "insightParameters": null,
          "measurement": "duplicateRowPercentage", // Using the row percetage
          "operator": "<=",
          "value": 0.0 // float, between 0-1
        }
      ],
      "subpopulationFilters": null,
      "mode": "development",
      "usesValidationDataset": true, // Apply test to the validation set
      "usesTrainingDataset": false,
      "usesMlModel": false,
      "syncId": "96622fba-ea00-4e42-8f42-5e8f5f60805f" // Some unique id
    }
  ]
  ```

  ```json Monitoring theme={null}
  [
    {
      "name": "No duplicate rows",
      "description": "Asserts that there are no duplicate rows",
      "type": "integrity",
      "subtype": "duplicateRowCount",
      "thresholds": [
        {
          "insightName": "duplicateRowCount",
          "insightParameters": null,
          "measurement": "duplicateRowCount", // Using the absolute row count
          "operator": "<=",
          "value": 0 // integer
        }
      ],
      "subpopulationFilters": null,
      "mode": "monitoring",
      "usesProductionData": true,
      "evaluationWindow": 3600, // 1 hour
      "delayWindow": 0,
      "syncId": "b4dee7dc-4f15-48ca-a282-63e2c04e0689" // Some unique id
    },
    {
      "name": "No duplicate rows",
      "description": "Asserts that there are no duplicate rows",
      "type": "integrity",
      "subtype": "duplicateRowCount",
      "thresholds": [
        {
          "insightName": "duplicateRowCount",
          "insightParameters": null,
          "measurement": "duplicateRowPercentage", // Using the row percetage
          "operator": "<=",
          "value": 0.0 // float, between 0-1
        }
      ],
      "subpopulationFilters": null,
      "mode": "monitoring",
      "usesProductionData": true,
      "evaluationWindow": 3600, // 1 hour
      "delayWindow": 0,
      "syncId": "96622fba-ea00-4e42-8f42-5e8f5f60805f" // Some unique id
    }
  ]
  ```
</CodeGroup>