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From Apache Wiki <wikidi...@apache.org>
Subject [Cassandra Wiki] Trivial Update of "FAQ" by JonathanEllis
Date Fri, 06 Sep 2013 02:23:53 GMT
Dear Wiki user,

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The "FAQ" page has been changed by JonathanEllis:
https://wiki.apache.org/cassandra/FAQ?action=diff&rev1=161&rev2=162

  <<Anchor(clocktie)>>
  == What happens if two updates are made with the same timestamp? ==
  
- Updates must be commutative, since they may arrive in different orders on different replicas.
 Thus, in the case of a timestamp tie, Cassandra follows two rules: first, deletes take precedence
over inserts/updates.  Second, if there are two updates, the one with the lexically larger
value is selected.
+ Updates must be commutative, since they may arrive in different orders on different replicas.
 As long as Cassandra has a deterministic way to pick the winner, the one selected is as valid
as any other, and the specifics should be treated as an implementation detail.  That said,
in the case of a timestamp tie, Cassandra follows two rules: first, deletes take precedence
over inserts/updates.  Second, if there are two updates, the one with the lexically larger
value is selected.
  

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