it seems that Talend is not caplable of performing a general self join.
In my opinion this is a standard ETL procedure and I'm wondering why this is the case.
I'm aware, that there is a work around by selecting the data twice. This is performance-wise not optimal.
Other ETL-Tools support a simple self join.
Is there another work around or a planned change for this?
If your data is coming out of a database, why not do the self join in the database? If there's a good reason not to, and you really don't want to have to run a query twice, you can throw your data into a Hash and use two tHashInput components to read from the same source.
True. Using a Hash is valid work around.
The reason not running a query on the db are the internal project guidelines. The guidelines demand to use talend for all occuring transformations.
Still I don't understand why we need to use a work around for this "simple" task.