THIS BLOCK IS THE SAME FOR ALL QUESTIONS
You must design a marketplace for landscapers.
A person can register as a landscaper. She then chooses the services she offers from a pre-established list. She then declares - by selecting on a calendar - her availability (a start date and an end date, the days are always whole).
Another person can register on the site as a client. She can then select the service or services she is looking for. A list of landscapers is then presented to her with a filter that allows only landscapers available for certain days / periods to be presented.
If the client finds an adequate landscaper, he can then select the dates he actually needs and then place an order.
All quiz questions refer to this problem.
####Two important constraints are added to answer the questions:
No data redundancy is tolerated.
We will consider the storage of structured data (table, hash, json, etc.) in a single data field impossible.
A client, in accordance with his right to the disposition of his personal data, wishes to delete his account. What operations must then be performed to preserve the past and future consistency of the data in the table?