Yes you can do scaled down testing in non-prod. An example test may try 100,000 or 1,000,000 operations when in production you might see 100,000,000. So you won't catch subtle performance problems but you'll catch order of magnitude problems (i.e something that is O(n) vs O(log(n))
Although in this case the test for this change may just EXPLAIN a known query and ensure the output matches what is expected.
Although in this case the test for this change may just EXPLAIN a known query and ensure the output matches what is expected.