The NOT IN handling with NULLs is the part I found most interesting, since that is where rewrites often go wrong. Beyond the regression tests, how do you check that a rewritten query matches the original? For example, running both against random data with lots of NULLs and comparing the results?
The NOT IN handling with NULLs is the part I found most interesting, since that is where rewrites often go wrong. Beyond the regression tests, how do you check that a rewritten query matches the original? For example, running both against random data with lots of NULLs and comparing the results?