Amazingly Stupid Query

I have to share this one. I'm working on a set of queries, tuning them. They're all following a similar pattern. They're passing in XML data sets which are then shredded into a temporary table. Once that's done, the temp table is used in a series of joins to other tables to return the data. Some of the queries were missing indexes, some were structured a bit poorly, but overall, it was pretty standard stuff. Until... I ran a query that looked, at first glance, the same as the rest. When I looked at the execution plan, I saw a warning symbol, one of those little exclamation points on an operator. I figured, based on the other issues with this database, that it was just some out of date or…
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