drop table if exists tbl ;
create temp table tbl
(
x polygon
);
insert into tbl(x) values ('(0,0),(0,10),(10, 10), (0, 5), (10,0), (0,0)');
select * from tbl where x @>'(5,5)'; --return empty
select * from tbl where x @>'(9.8,9.9)'; --return polygon
@> = to check point in polygon