I look at what the deal is with Polybase and Tar files:
The select statement returned 3104 records, exactly 4 shy of the 3108 I would have expected (777 * 4 = 3108). In each case, the missing row was the first, meaning when I search for LastName = ‘Turgeon’ (the first player in my data set), I get zero rows. When I search for another second basemen in the set, I get back four rows, exactly as I would have expected.
What’s really interesting is the result I get back from Wireshark when I run a query without pushdown: it does actually return the row for Casey Turgeon.
This isn’t an ideal scenario, but it did seem to be consistent in my limited testing.