I have a query that started behaving differently a couple days ago. We checked and on table in line 30 the stats were 1 month old, so we gathered new ones. But the estimate didn't change. Then checked the index in line 29, it's valid and has fresh stats too. That didn't help either.
This table has 10M+ rows and when I used USE_HASH hint, the estimate has gone back to the right 10M.
Is there anything else we could check? Thanks!