after2D before2D Bigintspan_spgist_config contain2D distance_span_nodespan Floatspan_spgist_config get_quadrant2D Intspan_spgist_config left2D overAfter2D overBefore2D overlap2D overLeft2D overRight2D Period_spgist_config right2D Set_spgist_compress SortedSpan Span_kdtree_choose Span_kdtree_inner_consistent Span_kdtree_picksplit span_level_cmp span_lower_qsort_cmp Span_quadtree_choose Span_quadtree_inner_consistent Span_quadtree_picksplit span_spgist_get_span Span_spgist_inner_consistent Span_spgist_leaf_consistent span_upper_qsort_cmp spannode_copy spannode_init spannode_kdtree_next spannode_quadtree_next Spanset_spgist_compress

span_level_cmp() static int span_level_cmp ( Span *  centroid, Span *  query, int  level  ) static Determine which half a 2D-mapped span falls into, relative to the centroid and the level number. Halves are numbered 0 and 1, and depending on whether the level number is even or odd, respectively, they will be as follows: ----+---- 0 | 1 ----+---- or --------- 1 --------- 0 --------- where the lower bound of the span is the horizontal axis and the upper bound is the vertical axis. Periods whose lower/upper bound is equal to the centroid bound (including their inclusive flag) may get classified into either node depending on where they happen to fall in the sorted list. This is okay as long as the inner_consistent function descends into both sides for such cases. This is better than the alternative of trying to have an exact boundary, because it keeps the tree balanced even when we have many instances of the same span value. In this way, we should never trigger the allTheSame logic.