All search APIs can be applied across multiple types within an index, and across multiple indices with support for the multi index syntax. For example, we can search on all documents across all types within the twitter index:
$ curl -XGET 'http://localhost:9200/twitter/_search?q=user:kimchy'
We can also search within specific types:
$ curl -XGET 'http://localhost:9200/twitter/tweet,user/_search?q=user:kimchy'
We can also search all tweets with a certain tag across several indices (for example, when each user has his own index):
$ curl -XGET 'http://localhost:9200/kimchy,elasticsearch/tweet/_search?q=tag:wow'
Or we can search all tweets across all available indices using
$ curl -XGET 'http://localhost:9200/_all/tweet/_search?q=tag:wow'
Or even search across all indices and all types:
$ curl -XGET 'http://localhost:9200/_search?q=tag:wow'