Group mysql query by 15 min intervals

Question

I\'ve got a monitoring system that is collecting data every n seconds (n is approximately 10 but varies). I\'d like to aggregate the collected data by 15 minute intervals.

Answer 1

Unix timestamps: floor them to nearest 15 minute using one of the following:

timestamp div (15 * 60) * (15 * 60) -- div is integer division operator
timestamp - timestamp % (15 * 60)

Date time: assuming the datatype does not have fractional seconds, floor them to nearest 15 minute using:

date - INTERVAL EXTRACT(SECOND FROM date) SECOND - INTERVAL EXTRACT(MINUTE FROM date) % 15 MINUTE

DBFiddle