Download a Data Dictionary

Alation Cloud Service Applies to Alation Cloud Service instances of Alation

Customer Managed Applies to customer-managed instances of Alation

Important

You are viewing documentation for Classic Alation.

You can download data dictionaries at the data source, schema, or table level. However, it’s not possible to download a dictionary for a single data object without its child objects if they exist. For example, you can download a data dictionary for a schema along with its child tables and columns, or for a table and its child columns. The name of the downloaded file includes the object type to indicate the level it was downloaded from, for example:

  • data_1_2_2024-06-05T21-04-30-358110—Data dictionary for a data source (the data object type)

  • schema_3_1_2024-06-04T22-39-14-612765—Data dictionary for a schema (the schema object type)

  • table_1_2_2024-06-05T20-37-20-835176—Data dictionary for a table (the table object type)

To learn more about the structure of the data dictionary file, see Data Dictionary Structure.

Note

If you are a Server Admin, be advised that certain aspects of the data dictionary download vary by Alation version.

  • Versions prior to 2023.3: Users can proceed with the instructions provided below.

  • Versions 2023.3 and 2023.3.1: Version 2023.3 introduced a new data dictionary download experience that is enabled by default. It features a new column, al_datadict_item_properties, in the downloaded data dictionaries, which may cause issues for users when they upload data dictionaries in these versions. The issues are caused by the change in the default server configuration for data dictionaries. Refer to Troubleshoot Data Dictionary Download and Upload for more details.

  • Versions 2023.3.2 and newer: The known issue has been resolved. The download and upload processes for data dictionaries have been significantly improved. Users simply follow the steps below to download data dictionaries.

To download a data dictionary:

  1. Sign in to Alation and open the catalog page of a data source.

    • If you want to download the complete data dictionary for this data source and all its child objects, download from the data source page.

    • If you need the data dictionary for one particular child object (for example, one of the schemas or tables), then navigate to the catalog page of the schema or table and download from there.

  1. In the upper-right corner, click the three-dot icon and then click Download Dictionary.

    ../../_images/DataDict_Neo_DownloadDictionaryButton.png

  1. In the upper-right corner, click More, and then click Download Dictionary.

    ../../_images/DataDict_DataMenu.png

  1. The Download Dictionary dialog opens.

    ../../_images/DataDict_DownloadDictionaryDialog.png

  2. In the dialog, select one of the available file formats—CSV, XML, or JSON—and click Confirm. As the download occurs asynchronously, a message appears at the bottom of the page informing you that the data dictionary is being processed and that an email confirmation will be sent when the data dictionary file is ready for download.

    ../../_images/DataDict_Neo_DownloadDD_Success.png ../../_images/DataDict_DownloadInProgress.png

    Note

    You can only create one data dictionary export at a time for any object or data source. You cannot queue a data dictionary export for the same data source multiple times when an export is already running. If you try to create another export on the same data source or object while a previous export is running, you see a warning that an export is already in progress. Wait for a few minutes and try again.

  3. When the data dictionary is ready for download, you receive an email containing a link to the prepared data dictionary. Click the link:

    • If you are already signed in to Alation, the file is downloaded.

    • If you are not signed in to Alation, the sign-in page opens when you click the link. The download occurs only after you sign in. The file is downloaded using the browser.

    Note

    The download file is stored on the server for five days. If you sign in to Alation and click the data dictionary download link five days after creating it, the download file will not exist and you’ll get a “link expired” error message.

If there is a problem with the download job, an email notification is sent to the user as depicted in the screenshot:

../../_images/DataDictionary05.png

A few issues that might occur while accessing the data dictionary download are the following:

  • If you sign in to Alation and click the download link and the file exists, but the signed-in user is different from the user who requested the download, the following warning is displayed: You need access to view this page.

  • If you access the downloadable link after the file expires, you’ll see the “link expired” error message. Data dictionary files are stored on the server for five days.