You can use certain search equations in eHive to structure your queries to perform more complex searches or to refine your results. Examples of these types of searches can be found in the sections on constructing searches in eHive and advanced searches.
eHive’s text indexing system
eHive searching relies on SOLR, a widely-used indexing system. The foundation of SOLR is Apache Lucene.
You can read more about Lucene query syntax here: Lucene Query Syntax
SOLR has a few minor differences: SOLR Query Syntax