Deleting by query 

Command for issuing a delete by query.

After you issue a delete by query, documents start getting deleted immediately and deletions continue until all documents are removed. For example you can delete the data that you inserted using this command on the operating system command line:

$ curl http://localhost:8983/solr/mykeyspace.mysolr/update --data
  '<delete><query>*:*</query></delete>' -H
   'Content-type:text/xml; charset=utf-8'

Using &allowPartialDeletes parameter set to false (default) prevents deletes if a node is down. Using &allowPartialDeletes set to true causes the delete to fail if a node is down and the delete does not meet a consistency level of quorum. Delete by queries using *:* are an exception to these rules. These queries issue a truncate, which requires all nodes to be up in order to succeed.