The latter is actually a primary key lookup against the parent table and constitutes the foreign key constraint verification.

索引扫描实际上是对父表进行主键查找，并完成外键约束验证。

youdao

The Mediterranean diet constitutes a set of skills, knowledge, practices and traditions ranging from the landscape to the table, including the crops, harvesting, fishing, conservation, processing, preparation and, particularly, consumption of food.

UNESCO: Culture