4 ms·
I think I know what they're getting at, but "can quickly saturate disk bandwidth" doesn't exactly sound like a selling point, on its own!
by Retr0id 3y ago
I think I know what they're getting at, but "can quickly saturate disk bandwidth" doesn't exactly sound like a selling point, on its own!
- lomereiter 3y agoReminds me of a Russian joke. A secretary applies for a job; the interviewer asks her: "In your CV you claim that you can type 1000 characters per minute - for real?!" "Yes!", she replies, then adds in a low voice: "but such nonsense comes out..."
- ww520 3y agoSSD have very good bandwidth, in excessive of 10 GB/s. The bottleneck is often at the CPU. For a 10Ghz CPU, it can spend 1 cycle to process 1 byte. That’s the scale we’re at now. https://www.tomshardware.com/features/ssd-benchmarks-hierarchy https://www.tomshardware.com/features/ssd-benchmarks-hierarc...
- klysm 3y agoHow is that not a selling point? You want the disk to be the bottleneck
- cout 3y agoNot necessarily. For example, an uncompressed log will saturate disk more easily than a compressed log but if compression is fast enough the compressed log will write more data in the same amount of time. A more complex case: a column store might write in batches. Later an insert in the middle might require the entire batch to be read from disk and then rewritten. This makes queries faster later on but at the cost of more disk io up front. In this case disk bandwidth is also saturated but write performance might be worse than an append-only log that does not optimize at all for reads/queries.
- klysm 3y agoThose are good points. Perhaps a better way to phrase it is you want the system to be able to utilize as much disk bandwidth as you give it.