Delete all documents from index without deleting index

Question

I believe if you combine the delete by query with a match all it should do what you are looking for, something like this (using your example):

curl -XDELETE 'http://localhost:9200/twitter/tweet/_query' -d '{
    "query" : { 
        "match_all" : {}
    }
}'

Or you could just delete the type:

curl -XDELETE http://localhost:9200/twitter/tweet

Note: XDELETE is deprecated for later versions of ElasticSearch