David Roberts b8f06df53f
[ML] Fix bug, add tests, improve estimates for estimate_model_memory (#54508)
This PR:

1. Fixes the bug where a cardinality estimate of zero could cause
   a 500 status
2. Adds tests for that scenario and a few others
3. Adds sensible estimates for the cases that were previously TODO

Backport of #54462
2020-03-31 17:59:38 +01:00
..