You always insert or load into, or delete from, the underlying tables, not the join index itself. When you first create the join index, Sybase IQ synchronizes the joined tables automatically, whether or not you have previously loaded data into the tables.
If you insert into or delete from a table that participates in an existing join index, you must synchronize the join index explicitly, unless you are updating the top table in the join hierarchy. If you insert rows and then delete them before the synchronization takes place, Sybase IQ optimizes synchronization to omit the insertions.
