What reasons can lead to the failure of a database migration process?

The reasons for migration process failure can be as follows:

• Schema mismatch: changes in table structures that conflict with current data or constraints.
• Migration script errors: syntax errors, incorrect execution order, or migration logic.
• Database access issues: insufficient permissions, database server unavailability.
• Version conflicts: incompatibility of DBMS or ORM versions with migration tools.
• Unexpected data: presence of data that violates new constraints (e.g., uniqueness, not null).
• Transaction issues: if migration does not support rollback, errors can lead to partially applied changes.

For successful migration, it is important to thoroughly test scripts, make backups, and control the order of migrations.