* This is a synchronous IO call, not an asynchronous IO call. If it were asynchronous, Oracle would have issued a different system call.

* Take a look at the requested block size and the number of blocks requested. If you are familiar with Oracle, you'll immediately notice that we are looking at an 8KB database, and Oracle is asking for 16 blocks at once. And you are correct if you guessed the instance parameter db_multiblock_read_count is 16!

Digging a little deeper, we can assert that all the requested blocks must have resided in memory (but not Oracle's buffer cache memory, since Oracle needed to request them from the operating system). We can make this assertion because a physical spinning IO device cannot return 16 nonsequential blocks (the blocks could be scattered over many physical devices) in less than a single millisecond!