Table Variables and Parallelism

Erik Darling shows off a neat trick for inserting with parallelism into a table variable:

One of the many current downsides of @table variables is that modifying them inhibits parallelism, which is a problem #temp tables don’t have.

While updating and deleting from @table variables is fairly rare (I’ve seen it, but not too often), you at minimum need an insert to put some data in there.

No matter how big, bad, ugly, or costly your insert statement is, SQL Server can’t parallelize it.

That’s just what he wants you to think and then the trap goes off.

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