Re: Read consistency when using synchronous_commit=off

Sorry I misunderstood.  The term "read consistency" is generally used either in the context of isolation level or in the context of slaves.

You are good.  All transactions update buffer cache too, along with WAL buffer and hence other sessions can immediately see the changes. synchronous_commit=off will only reduce the fsync calls, which makes them less crash safe, but the database consistency is not compromised.