the writer feature type is standard set to truncate the table, you can find that in the writer feature type parameters.

You can also consider using the DatabaseDeleter transformer.

To delete all records, specify a WHERE-clause that is always true, e.g.

As I understand it, a 'controller dataset' is one that participates in a network or some other type of feature class dependency. To delete or truncate you have to remove the feature class from the feature dataset. This short article might help

New response to an old post, but I've found a solution on my end for the "Operation is not supported on feature class in a controller dataset" issue. The issue for me is that I have a stand-alone gdb with a field containing a GUID data type. It's either that or the fact that the feature class is part of a topology ruleset (or both), but I'm thrown this error when I try to truncate a table in ArcGIS.

This worked for me...

• Set up your writer in FME workbench.
• Right-click the writer and select "Edit Parameters...".
• Under "Parameters", set the "Transaction Type: " to Edit Session rather than Transactions. Click "OK".
• Right-click the writer once again and select "Properties...".
• In the "Format Parameters" tab, set "Truncate Table first: " to Yes.

The trick was setting the transaction type to an edit session.

Cheers.

Ben

(running FME 2015.0 from data interoperability extension in ArcGIS 10.3.1)

Yes, this often does the trick. Just be aware that using an Edit Session writer is much, much slower than by transaction. If the slowdown is unacceptable, it may be faster to delete the topology, write the changes using transactions, and finally recreate the topology.