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This page explains how to preview data in the Cloud Data Fusion Studio so
that you can debug errors before you deploy and run a pipeline.
If you encounter errors, you can fix them while your pipeline is still in Draft
mode.
Cloud Data Fusion uses the first 100 rows of your source dataset to
generate the preview.
In Preview mode, the Studio page displays the status and duration of
the preview job. You can stop the preview job at any time. You can also monitor
the log events as the preview job runs.
Console
Check that each source, transformation, and sink has no errors. To
validate them, on the Cloud Data Fusion Studio page, go to the
node for each plugin and click Properties>Validate.
View your pipeline on the Studio page and click the Preview
toggle to the on position. Run, Duration, and Logs options
appear at the top of the Studio page canvas.
Optional: before you run the preview job, update the following settings
by clicking Configure.
Preview config: update the number of rows to preview.
Advanced options: update the pipeline and engine configurations.
For more information, see Manage pipeline configurations.
To start the preview job, click Run. When the preview job runs, no
data is written to the sink, but you can check that data is read
and written as expected when you deploy the pipeline.
Optional: after you run the preview job, to see what your data looks
like at each stage in the pipeline, click Preview data on nodes in
the pipeline that handle data, such as sources, sinks, and
transformations.
When you're finished previewing the data, exit Preview mode by clicking
the Preview toggle to the off position.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[[["\u003cp\u003eThis page outlines the process of previewing data in Cloud Data Fusion Studio to identify and fix errors in pipelines while they are still in Draft mode.\u003c/p\u003e\n"],["\u003cp\u003eCloud Data Fusion uses the initial 100 rows of your data to generate a preview, allowing you to assess how data will be handled within the pipeline.\u003c/p\u003e\n"],["\u003cp\u003eThe Studio page displays the status and duration of the preview job, which can be stopped at any time, and log events can be monitored in real time.\u003c/p\u003e\n"],["\u003cp\u003eYou can configure runtime arguments, the number of rows to preview, and advanced pipeline and engine settings before running the preview job.\u003c/p\u003e\n"],["\u003cp\u003eAfter the preview job has run, you can examine the data at various stages by clicking \u003cstrong\u003ePreview data\u003c/strong\u003e on sources, sinks, and transformations in the pipeline.\u003c/p\u003e\n"]]],[],null,["# Preview data\n\nThis page explains how to preview data in the Cloud Data Fusion Studio so\nthat you can debug errors before you deploy and run a pipeline.\n\nIf you encounter errors, you can fix them while your pipeline is still in Draft\nmode.\n\nCloud Data Fusion uses the first 100 rows of your source dataset to\ngenerate the preview.\n\nIn *Preview* mode, the **Studio** page displays the status and duration of\nthe preview job. You can stop the preview job at any time. You can also monitor\nthe log events as the preview job runs.\n**Note:** Actions and post-run actions are ignored when running a preview. To preview data, follow these steps: \n\n### Console\n\n1. Check that each source, transformation, and sink has no errors. To validate them, on the Cloud Data Fusion **Studio** page, go to the node for each plugin and click **Properties** \\\u003e **Validate**.\n2. View your pipeline on the **Studio** page and click the **Preview** toggle to the on position. **Run** , **Duration** , and **Logs** options appear at the top of the **Studio** page canvas.\n3. Optional: before you run the preview job, update the following settings\n by clicking **Configure**.\n\n 1. **Runtime arguments** : for more information see [Set up runtime arguments](/data-fusion/docs/how-to/manage-macros-prefs-and-runtime-args#set-up-runtime-arguments).\n 2. **Preview config**: update the number of rows to preview.\n 3. **Advanced options** : update the pipeline and engine configurations. For more information, see [Manage pipeline configurations](/data-fusion/docs/concepts/manage-pipeline-configurations).\n4. To start the preview job, click **Run**. When the preview job runs, no\n data is written to the sink, but you can check that data is read\n and written as expected when you deploy the pipeline.\n\n5. Optional: after you run the preview job, to see what your data looks\n like at each stage in the pipeline, click **Preview data** on nodes in\n the pipeline that handle data, such as sources, sinks, and\n transformations.\n\n6. When you're finished previewing the data, exit Preview mode by clicking\n the **Preview** toggle to the off position.\n\nWhat's next\n-----------\n\n- Learn how to [create pipeline alerts](/data-fusion/docs/how-to/create-alerts)."]]
