The following example (slightly modified from the one in the page) generates tables with lots of repetition, which could be easily avoided by truncation.
schema employee(eid:int, age:int, ??);
schema payroll(eid:int, salary:int, ??);
table uw_emp(employee);
table uw_payroll(payroll);
query q1
`select distinct e.eid as eid
from uw_emp e, uw_payroll p
where e.eid = p.eid`;
query q2
`select distinct e1.eid as eid
from uw_emp e1, uw_emp e2, uw_payroll p
where e1.eid = e2.eid and e1.eid = e2.eid`;
verify q1 q2;
The following example (slightly modified from the one in the page) generates tables with lots of repetition, which could be easily avoided by truncation.
Result:
Table
uw_payrollTable
uw_emp