Re:IO Devices and Latency
by crazygringo on Saturday March 15, 2025 @09:59AM
(#43372578)
Hundreds of microseconds? L1 access? I don't have the faintest idea of what you're talking about.
Communication between processes is negligible compared to all of the sequential disk/SSD accesses and processing required for executing queries.
The database isn't stored in L1 and communication isn't taking hundreds of microseconds. I don't know where you're getting your information.
The fact that SQLite is in-process is primarily about simplicity and convenience, not performance. Performance can even be worse, e.g. due to the lack of a query cache.
Same-core context switching costs a few microseconds.
Going across core complexes can cost tens to hundreds of microseconds.
These figures are several orders of magnitude (5-6) slower than L1 access on the same thread.