Foreign key constraints are not supported in Delta Lake, so data integrity must be enforced through application logic, which may increase development time and complexity.

Creating a Delta Lake table with foreign key constraints requires integrating a third-party library or external system, potentially introducing additional costs and complexity.

Delta Lake supports foreign key constraints natively, which can be defined using the ALTER TABLE statement to ensure data integrity without external dependencies.

Foreign key constraints can be simulated in Delta Lake using a combination of MERGE INTO and DELETE statements, but this approach may not fully guarantee data integrity under all scenarios.