Joins are used to define how rows in different tables relate to one another. In Information Designer, joins are defined as a join element that can be reused in multiple information links.
Normally an identifier column in one table maps to a similar column in another table. This allows information links to draw values from two or more different tables. When column elements from two or more data tables are to be retrieved within the same information link you must always include a join path at the creation of the information link. Joins can also be set up between tables in different data sources.
In the Elements tree, joins are represented by this icon:
From a technical point of view, join elements can be placed anywhere in the tree structure. The Suggest Joins button on the Information Link tab helps you to find suitable joins for the currently used elements. However, you might want to place joins where they can easily be found. Just like filter and column elements, join elements are under permission control. This means that you must make sure that the folder where the joins are located is accessible to all users and groups that need to create their own information links.
See also:
Creating a Join in Information Designer
Freehand Joins in Information Designer
Editing a Join in Information Designer
Deleting a Join in Information Designer