Where are joins performed during Information Link execution?

Where are joins performed during Information Link execution?

When executing an Information Link with data from more than one data source, a join will be performed by Information Services on the Spotfire Server. This is the logic used when determining which data source will be used by the server to perform the join.
  The Spotfire Server will use the first available data source from the following list.

1. The default join data source if defined in the Information Link (setting is DEFAULT_JOIN_DATA_SOURCE).
2. The first writable data source in the query's data source list (the list is sorted according to FIRST_ELEMENT_TARGET or LAST_ELEMENT_TARGET).
3. The first writable procedure data source.
4. The first writable join data source.
5. The default join data source.
6. The first (in alphabetic order) wriable data source.

If none of the above data sources are available or writable, then there will be an error that the join cannot be performed. Doc: Default join database:

• https://docs.tibco.com/pub/spotfire_server/7.11.0/doc/html/TIB_sfire_server_tsas_admin_help/GUID-6F746656-4EFC-4447-A76C-84DDBC8AA611.html