To improve query performance, the results of all GET requests are cached for a certain amount of time:
If you or another user with the same access level make a request for the same data set within this caching window, the results are identical. If your response is based on cached data, the date and time that the query was run is returned in the last_run_time field of the response metadata.
For example, if you request today's authorization transaction data at 9:00 am, and another user requests today's authorization transaction data at 9:05 am, the result sets are identical. If you make another request at 9:10 am, the API generates a new result set. Similarly, if you make a request for the week's authorization transaction data at 9:05 am, the API generates a new result set.