I use Google App Engine Search API, i dont know what is the name of the feature in image below, i want to delete the "customerindex" and "customers"

maybe the right question is "how to delete the search index?"
I use Google App Engine Search API, i dont know what is the name of the feature in image below, i want to delete the "customerindex" and "customers"

maybe the right question is "how to delete the search index?"