フリー問題

問題文

A team maps a tree of entities onto a database and leaves the strategy element of the root unwritten. Which layout does the provider fall back to, and what marks the origin of a row?

選択肢

1. The provider stores the whole tree in a table per subtype, and the origin of a given row is told from a discriminator column
2. The provider stores the whole tree in a single broad table, and the origin of a given row is told from the surrogate key
3. The provider stores the whole tree in a table per subtype, and the origin of a given row is told from the surrogate key
4. The provider stores the whole tree in a single broad table, and the origin of a given row is told from a discriminator column