Asynchronous Data Dictionary Download¶
Available from version V R6 (5.10.x)
Starting with Alation V R6, Data Dictionary export will be performed asynchronously. Users will request an export of a Data Dictionary, which is then prepared in the background, allowing users to continue to use Alation without having to remain on the same page. The asynchronous download comprises two steps: first, when a user requests an export of a data dictionary, a background job is launched to create and store the export file on the server. Second, when the file export is completed, an email having the download link of the dictionary is sent to the user’s email address. The user must click the downloadable link to access the exported dictionary. This feature helps users download larger data dictionaries.
Downloading a Data Dictionary¶
To download a data dictionary, follow these steps.
Sign in to Alation.
Click a data object. Data sources, schemas, and tables can be used to download a Data Dictionary. The catalog page opens up.
Click More… in the right upper-end corner of the screen.
Click Download Dictionary. The Download Dictionary window appears.
On the Download Dictionary window, select the File Type. The available options of File Type are CSV, XML, and JSON.
Click Confirm to acknowledge that the download status can be sent to your email address even if you have opted to stay out of Alation email notification:
If the download process is successfully launched,, a notification in green color will appear with the following text “Your export is processing and a link will be sent to <your_email>@alation.com.” (Specified email address of the user)
If the current user already has a download process running in the background for the chosen object, a notification in red color will appear with the following message “Your export is already in progress and a link will be sent to <your_email>@alation.com when complete”. Parallel downloads of multiple exports is not supported:
Accessing a Data Dictionary Download Using the Link¶
After the successful completion of the process of Data Dictionary export, an email having the download link is sent to the user.
Click the link. The Data Dictionary download requires that the user must have signed in to Alation. This ensures that it is the same user who has requested the download. If the user has already signed in to Alation, the file will get downloaded. If the user has not signed in to Alation, the sign-in page opens when the user tries to click the attachment. The download will occur only after the user signs in. The file will be downloaded using the browser.
Failure to Access a Data Dictionary Download Using the Link¶
If there is a problem with the download job, an email notification is sent to the user as depicted in the screenshot.
Potential Errors During Data Dictionary Download¶
A few errors that might occur while accessing the Data Dictionary download are the following:
The download file is stored on the server for only three days. If the user has signed in to Alation and clicked the Data Dictionary download link after three days, the download file will not exist and there will be a “link expired” error message.
If the user has signed in to Alation and clicked 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 ned access to view this page”.
A user can only create one 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, it will throw a warning that an export is already in progress.