Asset contents or previews
You can see the contents or a preview of the contents of most data assets and some other types of assets on the Asset page of an asset in a catalog. In projects and other workspaces, you can see a preview of data assets that contain relational data.
- Requirements and restrictions
- Previews of data assets
- Previews or contents of other types of assets in catalogs
Requirements and restrictions
You can view the contents or previews of assets under the following conditions and restrictions.
- Required service
- None. Previews are always visible.
- Workspaces
- You can view the preview or contents of assets in these workspaces:
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- Projects
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- Catalogs
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- Deployment spaces
- Types of assets
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- Data assets from files
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- Connected data assets
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- COBOL copybooks
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- Dashboards
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- Data quality definitions
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- Models
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- Model use cases
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- Notebooks
- Required permissions
- To see the asset contents or preview, these conditions must be true:
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- You have any collaborator role in the workspace.
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- In catalogs, you have access to the asset, either because the privacy setting for the asset is public, or you are a member of or the owner of the asset. See Controlling access to an asset.
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- In catalogs, you are not blocked by any data protection rules. See Data protection rule enforcement.
- Restrictions for data assets
- Additional requirements apply to connected data assets and data assets from files. See Requirements for data assets.
- Previews are not available for data assets that were added as managed assets by using the Watson Data API.
Previews of data assets
The previews of data assets show a view of the data.
You can see when the data in the preview was last fetched and refresh the preview data by clicking the refresh icon.
- Requirements for data assets
- Masking and filtering in previews of data assets
- Preview information for data assets
- File extensions and mime types of previewed files
Requirements for data assets
The additional requirements for viewing previews of data assets depend on whether the data is accessed through a connection or from a file.
- Connected data assets
- You can see previews of data assets that are accessed through a connection if all these conditions are true:
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You have access to the data asset and its associated connection. See Requirements and restrictions.
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The data asset contains structured data. Structured data resides in fixed fields within a record or file, for example, relational database data or spreadsheets.
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You have credentials for the connection:
- For connections with shared credentials, the username in the connection details has access to the object at the data source.
- For connections with personal credentials, you must enter your personal credentials when you see a key icon (
). This is a one-time step
that permanently unlocks the connection for you. See Adding connections to projects.
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- Data assets from files
- You can see previews of data assets from files if the following conditions are true:
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You have access to the data asset. See Requirements and restrictions.
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The file is stored in IBM Cloud Object Storage. For preview of text or image files from an IBM Cloud Object Storage connection to work, the connection credentials must include an access key and a secret key. If you’re using an existing Cloud Object Storage connection that doesn’t have these keys, edit the connection asset and add them. See IBM Cloud Object Storage connection.
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The file type is supported. See File extensions and mime types of previewed files.
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Masking and filtering in previews of data assets
The enforcement of data protection rules can result in masking data values or filtering rows from data assets. In a catalog, the asset owner always sees the original data asset without masking or filtering. In a project, all project collaborators see the asset the way it looks to the person who adds it from the catalog. After data protection rules or asset profiles are changed, rule enforcement can be delayed by up to one day until the asset previews are refreshed.
- Masked data values
- If data values in a column are masked by a data protection rule, you see a shield icon
next to the column name. Masked data can appear
as similarly formatted values or as meaningless values. See Masking enforcement. - Filtered rows
- If rows are filtered by a data protection rule, they don't appear in the preview. Under some circumstances, previews of filtered data assets are not available. See Previews might not be available.
Preview information for data assets
For structured data, the preview displays a limited number of rows and columns:
- The number of rows in the preview is limited to 1,000.
- The amount of data is limited to 800 KB. The more columns the data asset has, the fewer rows that appear in the preview.
Previews show different information for different types of data assets and files:
- Connected data assets
- The preview shows column names, data types, and a subset of columns and rows of data.
- Connected folder assets
- The preview shows the files and subfolders, which you can also preview.
- Relational data, CSV, Avro, partitioned data files, and Parquet files
- The preview includes column names, data types, and a subset of columns and rows of data.
- TSV files
- The preview includes column names, data types, and a subset of rows of data.
- Text, JSON, HTML, PDF, and images
- The preview shows the whole document. HTML files are supported in text format. Images stored in IBM Cloud Object Storage support JPG, JPEG, PNG, GIF, BMP, and BMP1. However, unstructured data files, like PDF files, or images stored outside IBM Cloud Object Storage are not supported.
- Microsoft Excel documents
- The preview shows the first sheet.
File extensions and mime types of previewed files
These types of files that contain structured data have previews:
| Extension | Mime type |
|---|---|
| AVRO | |
| CSV | text/csv |
| CSV1 | application/csv |
| JSON | application/json |
| PARQUET | |
| PARQ | |
| TSV | |
| TXT | text/plain |
| XLSX | application/vnd.openxmlformats-officedocument.spreadsheetml.sheet |
| XLS | application/vnd.ms-excel |
| XLSM | application/vnd.ms-excel.sheet.macroEnabled.12 |
These types of image files have previews:
| Extension | Mime type |
|---|---|
| BMP | image/bmp |
| GIF | image/gif |
| JPG | image/jpeg |
| JPEG | image/jpeg |
| PNG | image/png |
These types of document files have previews:
| Extension | Mime type |
|---|---|
| HTML | text/html |
| application/pdf | |
| TXT | text/plain |
Previews or contents of other types of assets in catalogs
Some other asset types show previews or contents on the Asset page of the asset in catalogs.
- COBOL copybooks and data from z/OS
- The Asset page shows the map metadata that is included with the IBM Data Virtualization Manager Data Mapping Facility on the mainframe computer.
- Dashboards
- The Asset page shows a snapshot of what the dashboard looks like. When you select to publish a dashboard to a catalog, you can choose to add screen captures of the dashboard with the dashboard file to the catalog. If a snapshot of the dashboard was added to the catalog, users can preview the snapshot before adding the dashboard from the catalog into another project.
- Data quality definition
- The Asset page shows rule logic that can be included in data quality rules.
- Models
- In catalogs, the Asset page shows information about the model and the model training.
- Model use cases
- The Asset page shows information about models through each stage of the model lifecycle and details about the models and deployments that are tracked in the use case.
- Notebooks
- The Asset page shows the whole notebook.
Learn more
Parent topic: Asset types and properties