PostGIS
2.5.0beta1devr@@SVN_REVISION@@

PG_FUNCTION_INFO_V1  (  gserialized_gist_sel  ) 
This function should return an estimation of the number of rows returned by a query involving an overlap check ( it's the restrict function for the && operator )
It can make use (if available) of the statistics collected by the geometry analyzer function.
Note that the good work is done by estimate_selectivity() above. This function just tries to find the search_box, loads the statistics and invoke the workhorse.