# Elastic search cheat sheet

#### GET data

	GET http://localhost:9200/:index/:type/:id

#### PUT (or update) data

	PUT http://localhost:9200/:index/:type/(:id)


#### Check data existence

	HEAD localhost:9200/:index/:type/:id

#### DELETE data
	
	# All resources
	DELETE http://localhost:9200/_all
	
	# An index
	DELETE http://localhost:9200/:index
	
	# A type
	DELETE http://localhost:9200/:index/:type
	
	# An item
	DELETE http://localhost:9200/:index/:type/:id

#### Searching

The `hits` object gives you the top 10 hits that matched the query. The `score` represents how well the results matched the query.

	# Empty searches

	# Entire database
	GET http://localhost:9200/_search
	
	# One index
	GET http://localhost:9200/:index/_search
	
	# Multuple indecies
	GET http://localhost:9200/:index,:index/_search
	
	# Wildcards
	GET http://localhost:9200/hub*/_search

##### Pagination
	
	# Page 1
	GET http://localhost:9200/_search?size=5&from=0
	
	# Page 2
	GET http://localhost:9200/_search?size=5&from=5

##### On fields

Good for development, not for production. If you do not specify a field, elasticsearch automatically uses the `_all` field, which searches through all fields.

	GET /_search?q:fieldName:query

#### Datatype mapping

When you insert data into elastic search, it uses dynamic detection to determine what kind of data each field is.

##### Get mapping

	GET http://localhost:9200/:index/:type/_mapping

##### Changing mapping

* If you are adding fields, there is no need to reindex.
* If you need to change a field, you need to reindex your data. [An article on the subject](http://www.elasticsearch.org/blog/changing-mapping-with-zero-downtime/)

##### Reindex data

**Lookup more detailed information on how to do this**

* Create a new index with the new mapping (see PUT mapping below)
* Pull in documents from the old index using a [scrolled search](http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-request-scroll.html) and index them to the new index using the [bulk API](http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/docs-bulk.html). Note: make sure that you include search_type=scan in your search request. This disables sorting and makes "deep paging" efficient.
* Update [index alias](http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/indices-aliases.html).
* Delete the old index


##### PUT (or update) mapping

	PUT http://localhost:9200/:index/:type -d '{
		"mappings": {
			"tweet": {
				"properties": {
					…
				}
				
			}
		}
	}'