common_entry_cmp PLACE_LEFT PLACE_RIGHT Set_gist_compress span_gist_consider_split Span_gist_consistent Span_gist_distance span_gist_double_sorting_split span_gist_fallback_split Span_gist_fetch span_gist_get_span Span_gist_penalty Span_gist_picksplit Span_gist_same Span_gist_union spanbounds_cmp_lower spanbounds_cmp_upper Spanset_gist_compress

Span_gist_distance() Datum Span_gist_distance ( PG_FUNCTION_ARGS  ) GiST distance method for span types. Note Take in a query and an entry and return the "distance" between them