Delete all documents from index before indexing new set


My jdbc input plugin is getting all the new documents which needs to be indexed. I do have a requirement to delete all the documents before indexing the new set. Please suggest me how i can delete my old documents which are already there.

Should i use http output plugin before by elasticsearch ? I see delete-by-query suites me.
how can we set the data (query) to the HTTP url in my logstash configuration?


It's more efficient to delete the index and create another.