Example 1

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;

Example 2

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;

Example 3

SELECT field1 FROM A, B WHERE A.field1 3D B.field1;