QUERY: create table G_ERR (x int4, y int4, z int4);
QUERY: select x from G_ERR group by y;
x  
-- 
QUERY: select x, sum(z) from G_ERR group by y;
WARN:parser: illegal use of aggregates or non-group column in target list
QUERY: select x, count(x) from G_ERR;
WARN:parser: illegal use of aggregates or non-group column in target list
QUERY: select max(count(x)) from G_ERR;
WARN:parser: aggregate can only be applied on an attribute
QUERY: select x from G_ERR where count(x) = 1;
WARN:parser: aggregates not allowed in WHERE clause
QUERY: create table H_ERR (a int4, b int4);
QUERY: select y, a, count(y), sum(b)
from G_ERR, H_ERR
where G_ERR.y = H_ERR.a group by y;
WARN:parser: illegal use of aggregates or non-group column in target list
QUERY: drop table G_ERR, H_ERR;
