CREATE OR REPLACE FUNCTION sliver_killer(geometry,float) RETURNS geometry AS
$$ SELECT ST_BuildArea(ST_Collect(a.geom)) as final_geom
FROM ST_DumpRings($1) AS a
WHERE a.path[1] = 0 OR
(a.path[1] > 0 AND ST_Area(a.geom) > $2)
$$
LANGUAGE 'sql' IMMUTABLE;

UPDATE merged SET geom = sliver_killer(geom,50::float);

SELECT st_buffer(st_buffer(geom,1,'join=mitre'),-1,'join=mitre') FROM mygeotable;

SELECT st_intersection(st_buffer(st_buffer(geom,-1,'join=mitre'),1,'join=mitre'),geom) FROM mygeotable;

SELECT st_intersection(
          st_buffer(
             st_buffer(geom, 1, 'join=mitre mitre_limit=1.0'
          ), -1, 'join=mitre mitre_limit=1.0'
        ), geom) as
FROM _mygeotable_ ;