Exam DP-203 topic 2 question 28 discussion

The answer is correct

The question and answer do not match. The question asks for "the difference in THE NUMBER OF READINGS per sensor per hour". The answer given is to compute the difference between the current sensor reading and the sensor reading from an hour ago.

Correct. Choosing the Right Function: When you need to compare a value with its future occurrences: Use LEAD. When you need to analyze dependencies or trends based on past values: Use LAG. When you want to identify the maximum or minimum for a group based on a specific order: Use LAST.

Correct, cgatpgt : To calculate the difference in the number of readings per sensor per hour using an Azure Stream Analytics query, you would use the LAG function to access the previous value and then calculate the difference. Here is how you would complete the query: - Use `LAG` to get the previous reading. - Use `LIMIT DURATION` to set the window of time for comparison, which in this case is per hour. The completed query would look something like this: ```sql SELECT sensorId, reading - LAG(reading) OVER (PARTITION BY sensorId LIMIT DURATION(hour, 1)) AS growth FROM input ``` This query assumes `reading` is the column holding the sensor data and `sensorId` is the column to partition the data by each sensor. The `LAG` function gets the last reading for the same sensor from the previous hour, and then you subtract this value from the current reading to find the growth.

should be correct

LAG is the correct answer. Refer the below link. It mentions this example https://learn.microsoft.com/en-us/stream-analytics-query/lag-azure-stream-analytics

right answer

what about LAST?

Answers as revealed are for computing the rate of growth per sensor. https://docs.microsoft.com/en-us/stream-analytics-query/lag-azure-stream-analytics#examples