Random Sampling Without Replacement | Dataford Interview Questions

How would you randomly sample K elements from a list without replacement?

Use the provided randomized ordering value for each element. Return no more than the requested number of available elements for each request.

Output

One row per selected element, with request_id, list_id, element_id, element_value, and sample_position.
Include only selected available elements, ordered by request_id, then sample_position, then element_id.

sampling_requests

Column	Type	Description
request_idPK	INT	Unique sampling request identifier
list_id	INT	List to sample from
k	INT	Maximum number of elements to select

list_elements

Column	Type	Description
element_idPK	INT	Unique element identifier
list_id	INT	List containing the element
element_value	VARCHAR(100)	Value associated with the element
random_key	DECIMAL(5,4)	Randomized ordering value
is_available	BOOLEAN	Whether the element may be sampled

Your question is Random Sampling Without Replacement. Start with the requirements and the two tables in the Question tab.

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