Joining Data Sources

Topics: Types of Joins How the JOIN Command Works Creating an Equijoin Using a Conditional Join Preserving Virtual Fields During Join Parsing Displaying Joined Structures Clearing Joined Structures

You can join two or more related data sources to create a larger integrated data structure from which you can report in a single request. The joined structure is virtual: it is a way of accessing multiple data sources as if they were a single data source. Up to 16 joins can be in effect at one time, for a total of 64 segments, depending on the number of active segments and the number and length of the fields (there is a 32K limit on the length of all fields). With the exception of comma‑delimited, tab-delimited, or token-delimited files, you can join any supported data source type. For details, see Data Sources You Can and Cannot Join.