SELECT * FROM A, B WHERE A.field1 3D B.field1; evaluates to: SELECT A.field1, A.field2, B.field1, B.field2 FROM A, B WHERE A.field1 3D B.field1;
SELECT A.field1, B.* FROM A, B WHERE A.field1 3D B.field1; evaluates to: SELECT A.field1, B.field1, B.field2 FROM A, B WHERE A.field1 3D B.field1;
SELECT field1 FROM A, B WHERE A.field1 3D B.field1;