Option A: remove the constraints Option B: make a table which is a copy of the entity table, but lacks the constraints. Load your data into that. Once the data is all there (which I think means there will be no NULLs left) copy that table to the real table using the <code>INSERT … SELECT</code> command which is optimized for speed. Then <code>DELETE FROM</code> your temporary table. Comment on your post: > given that hundreds of tables are involved This is always a red flag in a SQL database. If two tables have the same definition, or your table names include numbers or dates, it's probably a sign that they should be the same table, with one extra column. If you're right now at a stage where you are designing the schema, think hard about this because it will save you a lot of trouble in the long run.