I'm looking for some factual knowledge about INSERT statement performance, not conjecture with "probably" or "I imagine."
Does one of these have better performance, or does it not really matter?
A) Using an "INSERT A... SELECT... FROM B... WHERE NOT EXISTS (SELECT FROM A... WHERE B.PrimaryKey = A.PrimaryKey);" style statement.
B) Create table A with IGNORE_DUP_KEY on the primary key and let the database engine reject the duplicates for me?
Thank you in advance,