I am attempting to benchmark a number of queries over a 15GB dataset with ~ 10mil records. When I run linux time on the query execution (single column projection), it returns 1 minute, but the \timing command returns only 15 seconds? Can someone explain the difference? 1 minute is consistent with reading the 15gb from disk at 250mb/s (I have SSDs), but is \timing supposed to include that cost? Or simply the computation time plus the time to return results.
Thank you.