Thanks guys for your advice. The table is very large - about 250GB. I'd rather not have to make a duplicate of the data if I don't have to. Would it be advisable to simply alter the table "in place":

1) Drop the primary key

2) Alter the column to BigInt

ALTER TABLE FactInventory

ALTER COLUMN FactInventoryId BIGINT NOT NULL

3) Reapply the PK

ALTER TABLE ADD CONSTRAINT PK_FactInventoryId

PRIMARY KEY NONCLUSTERED (FactInventoryId)

Thoughts?

Peter