A single 5-million row INSERT can be a huge problem, it may fill up the transaction log even if the database is in simple recovery. A minimally-logged bcp insert is probably the best way to handle it as one file while minimizing this impact.
FYI, SSIS does not generate a single insert when loading data to a table. Also, 5 million rows is not a huge insert that would take multiple hours. Even my laptop could handle that within a few minutes.
Luis C.
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