> Finally MySQL gets performance in these large setups by turning off features like foreign keys, acid guarantees etc. Large MySQL users are generally not turn

> Finally MySQL gets performance in these large setups by turning off features like foreign keys, acid guarantees etc. Large MySQL users are generally not turning off acid guarantees. That is nonsense. What settings are you even specifically referring to with this? On the durability side, large MySQL shops only mess with innodb_flush_log_at_trx_commit if there's a safe distributed durability mechanism in use (e.g. synchronous or semi-synchronous replication). Or perhaps if the data is ephemeral/recomputable, but that's a similar use-case to running Postgres on a ramdisk. On the isolation side, MySQL supports READ UNCOMMITTED (unlike Postgres) but it is very rarely used. Only useful for some specific situations. fwiw MS SQL Server supports it too, it's not a MySQL specific thing.