Scan or random reads
Metal 03Estimate
A query reads 16 MiB of rows from main memory. A sequential scan streams at 20 GB/s. An index lookup reads the same bytes as random 64-byte lines, one after another, and each line waits 100 ns for memory. How many ms do the random reads take?
10 µs100 µs1 ms10 ms100 ms1 s10 s100 s1,000 s
Type a number or drag the scale. Each mark is 10 times the mark before it.