count documents using stored fields only in Apache solr

[Hafiz Shafiq]

I am using solr 4.10.3. Documents are indexed using apache nutch 2.3. There
is a field in schema.xml that is tstamp that contains informas when
documents was indexed. This field is not indexed and stored only in solr. I
want to count no of documents indexed by nutch in solr. It is clear that I
have to use tstamp field. Now how I can do it?