Understanding the process to display sample data

If you open a Column, Table or Data Set asset page, Collibra performs a series of checks to determine if sample data is displayed.

Note 

Currently, you can request sample data via Edge only for Table and Column assets.

Check or Action Description Positive outcome Negative outcome
1 Collibra checks if you have the required permissions to view sample data.

You have the required permissions:

  • The process continues with the next check.

You don't have the required permissions:

  • You cannot see the sample data and a message appears on the page.
  • The process stops.
2

Collibra checks if sample data is stored in the Collibra cloud repository.

Tip 

This is only possible if:

  • Sample data was extracted during the registration of the data source via Jobserver.
  • Sample data was uploaded by using the Catalog REST API - Profiling.

Sample data is available in the Collibra cloud repository:

  • The sample data is visible in the page.
  • The process stops.

No sample data is available in the Collibra cloud repository:

  • The process continues with the next check.
3

Collibra checks if the asset is connected to an Edge site.

An asset is connected to an Edge site when the asset has been registered via the Edge Catalog data source registration process. Only adding the Catalog JDBC Sampling capability to your Edge site is not enough. The asset is connected to the Edge site via its related Database asset.

The asset is connected to an Edge site:

  • The process continues with the next check.

No sample data is available for the asset:

  • You cannot see the sample data.
  • The process stops.
4 Collibra checks if sample data is available in the cache of Edge.
This is possible if sample data has been requested before and the cache has not been cleared in the meantime.

Sample data is available in the cache:

  • The sample data is visible in the page.

    Important It can take some time for the sample data to be displayed. Don’t navigate away from the page while the process is ongoing.

  • The process stops.

No sample data is available in the cache:

  • The process continues with the next check.
5 Collibra checks if a sample data request is pending for the data source.

A sample data request is pending for the data source:

  • You need to wait until the sample data has been collected and cached in the Edge site.
  • The process stops.

No sample data request is pending for the data source:

  • The button Request Sample Data appears on the page and in the Action drop-down list.
  • The process stops until you click the button.
6 You click the Request Sample Data button.
  • A 'Request sample data' job is launched and added to the Activities list and job queue.
  • When Edge is ready for the job, the job starts.
  • Sample data is randomly collected and temporarily made available in the cache of the Edge site.
    We randomly collect rows from the data source. The data of the randomly collected rows, however, is not switched around, we display all data for each randomly collected row.
    If you request sample data for a column, sample data is collected and cached for the entire table.
  • Because it can take time for the job to start and complete, you can navigate away from the page while the job is in progress.
  • Once the job is completed, you receive a notification.
  • The process stops.

Note Columns mapped to following java.sql.Types are excluded from the sampling queries: ARRAY, BINARY, BLOB, CLOB, DATALINK, DISTINCT, JAVA_OBJECT, LONGVARBINARY, NCLOB, NULL, OTHER, REF, REF_CURSOR, ROWID, SQLXML, STRUCT, VARBINARY.