Twenty thousand queries that only ever pair one rule type with one query shape have covered very little. These two charts answer “did you only test the easy cases?”

All 17 access-rule shapes
Bar length is the share of cases where enforcement-off would have returned unauthorised rows. Unauthorised rows returned with enforcement on: 0 in every shape.
Figure 4. No rule shape was exercised trivially. MULTI at 88% and CONFLICT_RESTRICTIVE at 87% are the adversarial ones — overlapping and conflicting rules, which is where real enterprise policy lives.
Ten SQL structures, including the ones that break naive rewriters
Share of cases where a leak was available to detect, by the structure stacked onto the seed query.
Figure 5. OR-tautology is the injection-style case — a query written to defeat a naive filter — and the one where a leak was most often available. UNION, CTE, INTERSECT and EXCEPT are the shapes that produced three real bugs in our own rewriter before they could reach a customer.