pub enum CommitTier {
None,
Ordered,
Durable,
}Expand description
Synchronization strength for one commit.
This setting has no effect unless DurabilityMode::Durable is selected.
In the default DurabilityMode::Derived mode it is ignored entirely and
no synchronization primitive is issued, including when this value is
Ordered or Durable.
Variants§
None
Buffer writes without synchronization; the page cache covers an application crash, but not a power cut.
Ordered
Order earlier writes before later writes with the platform barrier.
This default tier chooses a cheaper median than full durability on the measured development device, with a materially wider latency tail: barrier p95 varied 7.40x while full-sync p95 varied 1.02x. That spread is a device property, not buffering or timing behavior in this code.
Durable
Flush writes through to durable media with the platform full sync. Its measured 4 KiB median was 20.8x the ordered barrier median, but its latency distribution was substantially more stable on the same device.