I've reverted SEARCH. Sorry for the inconvenience. Here's the PR that re-adds SEARCH: https://github.com/apache/calcite/pull/2263 Please feel free to pick it up. I expect certain commits should be squashed (e.g. search should be re-added as a single commit).
I'm not sure I would have time to make it happen. Frankly speaking, I would suggest we should make SEARCH operator never return null. In other words, SEARCH(X, [Y, Z]) should be the same as "(X is not distinct from Y) or (X is not distinct from Z)". The old semantics was like SEARCH(null, [42]) => unknown, SEARCH(null, [null, 42]) => false which results in wrong results in simplification. "Expand search" might want to receive unknownAs parameter. Vladimir
