That common approach is both elegant and tricky. It requires very precise clocks and time synchronization, as some non-commutative operations are order-dependent (such as list insertion).<p>That is why Google&#x27;s TrueTime API (introduced in Spanner[0]) is such a big deal.<p>[0]: <a href="http:&#x2F;&#x2F;static.googleusercontent.com&#x2F;external_content&#x2F;untrusted_dlcp&#x2F;research.google.com&#x2F;en&#x2F;us&#x2F;archive&#x2F;spanner-osdi2012.pdf" rel="nofollow">http:&#x2F;&#x2F;static.googleusercontent.com&#x2F;external_content&#x2F;untrust...</a>