You can clear the contents of an index in the Index Landscape window in the context menu with function Clear Index. The index and its parameters are retained.
You only use this function in the following cases:
You have created an index with the TREX admin tool and want to empty it.
Application-side errors have occurred that SAP Support has told you can only be solved by emptying the index on TREX side.
The application that is connected to TREX receives no information on the emptying of the index. This means that the information the application stores on the index is not the same as the information TREX has. You may no longer be able to administrate the index on the application side.