[elasticsearch] Delete all documents from index/type without deleting type

I know one can delete all documents from a certain type via deleteByQuery.

Example:

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

But i have NO term and simply want to delete all documents from that type, no matter what term. What is best practice to achieve this? Empty term does not work.

Link to deleteByQuery

Starting from Elasticsearch 2.x delete is not anymore allowed, since documents remain in the index causing index corruption.

The Delete-By-Query plugin has been removed in favor of a new Delete By Query API implementation in core. Read here

curl -XPOST 'localhost:9200/twitter/tweet/_delete_by_query?conflicts=proceed&pretty' -H 'Content-Type: application/json' -d'
{
    "query": {
        "match_all": {}
    }
}'

If you want to delete document according to a date. You can use kibana console (v.6.1.2)

POST index_name/_delete_by_query
{
      "query" : {
              "range" : {
                 "sendDate" : {
                     "lte" : "2018-03-06"
                              }
                        }
                  }
}

Just to add couple cents to this.

The "delete_by_query" mentioned at the top is still available as a plugin in elasticsearch 2.x.

Although in the latest upcoming version 5.x it will be replaced by "delete by query api"

You can delete documents from type with following query:

POST /index/type/_delete_by_query
{
    "query" : { 
        "match_all" : {}
    }
}

I tested this query in Kibana and Elastic 5.5.2

The above answers no longer work with ES 6.2.2 because of Strict Content-Type Checking for Elasticsearch REST Requests. The curl command which I ended up using is this:

curl -H'Content-Type: application/json' -XPOST 'localhost:9200/yourindex/_doc/_delete_by_query?conflicts=proceed' -d' { "query": { "match_all": {} }}'

Note for ES2+

Starting with ES 1.5.3 the delete-by-query API is deprecated, and is completely removed since ES 2.0

Instead of the API, the Delete By Query is now a plugin.

In order to use the Delete By Query plugin you must install the plugin on all nodes of the cluster:

sudo bin/plugin install delete-by-query

All of the nodes must be restarted after the installation.

The usage of the plugin is the same as the old API. You don't need to change anything in your queries - this plugin will just make them work.

*For complete information regarding WHY the API was removed you can read more here.

Elasticsearch 2.3 the option

    action.destructive_requires_name: true

in elasticsearch.yml do the trip

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

You have these alternatives:

1) Delete a whole index:

curl -XDELETE 'http://localhost:9200/indexName'             

example:

curl -XDELETE 'http://localhost:9200/mentorz'

For more details you can find here -https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-delete-index.html

2) Delete by Query to those that match:

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

*Here mentorz is an index name and users is a type

In Kibana Console:

POST calls-xin-test-2/_delete_by_query
{
  "query": { 
    "match_all": {}
  }
}

From ElasticSearch 5.x, delete_by_query API is there by default

POST: http://localhost:9200/index/type/_delete_by_query

{
    "query": { 
        "match_all": {}
    }
}

(Reputation not high enough to comment) The second part of John Petrone's answer works - no query needed. It will delete the type and all documents contained in that type, but that can just be re-created whenever you index a new document to that type.

Just to clarify: $ curl -XDELETE 'http://localhost:9200/twitter/tweet'

Note: this does delete the mapping! But as mentioned before, it can be easily re-mapped by creating a new document.

I'm using elasticsearch 7.5 and when I use

curl -XPOST 'localhost:9200/materials/_delete_by_query?conflicts=proceed&pretty' -d'
{
    "query": {
        "match_all": {}
    }
}'

which will throw below error.

{
  "error" : "Content-Type header [application/x-www-form-urlencoded] is not supported",
  "status" : 406
}

I also need to add extra -H 'Content-Type: application/json' header in the request to make it works.

curl -XPOST 'localhost:9200/materials/_delete_by_query?conflicts=proceed&pretty'  -H 'Content-Type: application/json' -d'
{
    "query": {
        "match_all": {}
    }
}'
{
  "took" : 465,
  "timed_out" : false,
  "total" : 2275,
  "deleted" : 2275,
  "batches" : 3,
  "version_conflicts" : 0,
  "noops" : 0,
  "retries" : {
    "bulk" : 0,
    "search" : 0
  },
  "throttled_millis" : 0,
  "requests_per_second" : -1.0,
  "throttled_until_millis" : 0,
  "failures" : [ ]
}

Torsten Engelbrecht's comment in John Petrones answer expanded:

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

(I did not want to edit John's reply, since it got upvotes and is set as answer, and I might have introduced an error)