-- Function: makegrid_epsg3857(text, text, text, numeric)

-- DROP FUNCTION makegrid_epsg3857(text, text, text, numeric);

CREATE OR REPLACE FUNCTION makegrid_epsg3857(schemaname text, boundingbox text, gridtable text, halfwidth numeric)
  RETURNS text AS
$BODY$
    DECLARE
    tbl_cnt int;
    XMIN numeric;
    XMAX numeric;
    YMIN numeric;
    YMAX numeric;
    x_value numeric;
    y_value numeric;
    x_count integer;
    y_count integer;
    y_offset ...