estimates the number of distinct field values in the aggregation , which is always 1 . concode_field_sep Plan p concode_elem_sep Map<String,String> schemaFields concode_elem_sep Collection<String> groupByFields concode_elem_sep Schema schema concode_elem_sep Map<String,String> schemaAggs concode_field_sep Schema schema concode_elem_sep int blocksAccessed concode_elem_sep int recordsOutput concode_elem_sep Scan open
int function ( String arg0 ) { return 1 ; }