Join analysis is generated across and within data sources against the intersection of one or more sets of attributes. Each join consists of data elements that represent the left-hand and right-hand sides of the join analysis. These intersections, or joins, help you to understand data relationships.
Use the Create or Discover Joins window to guide you through the Sources, Attributes, and Join tabs (depending on the type of join you are adding), which include the following tasks:
- Select the type of join to add, permanent (created) or discovered
- Choose the data sources and attributes on which to join
- Configure join analysis options
- Verify the settings
There are two types of joins analysis you can add to the repository depending on your needs:
- Permanent—Reviewed and verified known join relationship you want to save for further use.
- Discovered—Potential join discovered as a possibly useful relationship but not yet reviewed for validity. You can find (discover) potential attribute joins between multiple data sources. Each potential join shows how an attribute from one data source relates to an attribute from another. You can then save (set as permanent) those joins that are important to your analysis and delete the ones that you do not need.
- Add joins using profiled (fully-loaded) data sources only. Dynamic data sources are not supported.
- Joins are added to the repository to which you are currently logged in.
- After you add a join, you can change its status at any time. For example, when you add a potential (discovered) join you can then change its status to permanent after you validate the join analysis is useful.
- If you create a permanent join and the total number of rows generated exceeds 2^32 (4294967296), some join metadata drill-down views may be unavailable.
- After you add joins, you can drill-down to see the data rows where the left-hand and right-hand data sources intersect. You can also open a Venn Diagram to help you visually understand the data relationships.
- Data sources and attributes are configured by default in the Trillium Control Center to be included in discovered join analysis. If this feature has been disabled, or if you want to remove an attribute or data source from discovered join analysis, in the Control Center open the attribute properties or edit the data source (entity) details and reset them. See the TSS Help for more information.
Using the Create or Discover Joins Window
The Create or Discover Joins window guides you through the process of adding a permanent or discovered join to the current repository based on the data sources and attributes you select. Your work is saved as you continue through the tabs. At any time during the process you can view a summary of your selections and make edits to your work. Navigate to other areas of the Discovery Center as needed while the window is open.
To open and use the Create or Discover Joins window
-
Do one of the following:
- On the Home page, go to the Add panel. In the Choose a category drop-down list, select New Join Analysis,then click the plus button ().
- In the left navigation menu, select Data Discovery > Add Join Analysis.
- Run a joins analysis search. From the search results page, click Add New Join Analysis.
- Open a data source. On the Summary tab, in the Relationships table, click
the Joins plus button(
).
The Create or Discover Joins window opens with the Sources tab active.
- Optional:
To change the size of the window:
Drag any corner or side of the window to resize it.
- Click
to expand the window.
Click 
again to return to the
original size. - Click
to collapse the window
down to a bar. Click to return to
the original size.
- Click
-
To edit your selections:
- Click the Sources or Attributes (permanent joins only) tab when it shows a green check.
- Click Summary at any time to see an overview of your saved selections. From the Summary page:
- Click the edit button (
) for the step you want to edit. This closes the
Summary and opens the step for editing. - Click Back or In Progress to open the last step you worked on.
Note: When you return to a tab to edit information, verify the selections on other tabs because they will need to change based on your edits. For example, if you are working on the Attributes tab for a permanent join and you go back to the Sources tab and select a different data source, you will need to reselect the left-hand and right-hand attributes on the Attributes tab.Clicking Finish adds the join to the current repository. To close the window at any time without saving your work, click Cancel or the X icon.