Minimal Logging When Inserting into Heaps

Paul White gives us the lowdown on minimal logging when performing INSERT..SELECT operations into heap tables:

When inserting rows using INSERT...SELECT into a heap with no nonclustered indexes, the documentation universally states that such inserts will be minimally logged as long as a TABLOCK hint is present. This is reflected in the summary tables included in the Data Loading Performance Guide and the Tiger Team post. The summary rows for heap tables without indexes are the same in both documents (no changes for SQL Server 2016):

But it’s not quite that straightforward, as Paul shows. Read the whole thing.