- What is a database migration?
The database migration (or schema migration) is the automatic management of updates to the database schema. The changes to the schema are incremental, usually reversible, and applied in the moment the database schema needs to be changed in order to reflect changes in the application code.
- Describe what could be an alternative approach to discarding an order completely, in the case of insufficient stock for some articles?
One of the alternatives could be to satisfy orders for all articles for which there are sufficient stock. This could be implemented by running each inventory update in a separate transaction and combining the results of all of them that succeeded.
Yet another alternative would be to satisfy orders as fully as possible. This approach would require selecting rows for update, calculating new possible states, and applying...