It's not just better performance on latency benchmarks, it likely improves throughput as well because the writes will be batched together.

Many applications do not require true durability and it is likely that many applications benefit from lazy fsync. Whether it should be the default is a lot more questionable though.

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johncolanduoni 3 hours ago | parent | next [-]

It’s like using a non-cryptographically secure RNG: if you don’t know enough to look for the fsync flag off yourself, it’s unlikely you know enough to evaluate the impact of durability on your application.

	▲	traceroute66 an hour ago \| parent [-]
		> if you don’t know enough to look for the fsync flag off yourself, Yeah, it should use safe-defaults. Then you can always go read the corners of the docs for the "go faster" mode. Just like Postgres's infamous "non-durable settings" page... https://www.postgresql.org/docs/18/non-durability.html

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senderista an hour ago | parent | prev [-]

For transactional durability, the writes will definitely be batched ("group commit"), because otherwise throughput would collapse.