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From Michael Greene <>
Subject Re: why does remove need a timestamp?
Date Mon, 09 Nov 2009 05:10:09 GMT
The remove call does not need the timestamp of what you inserted, it
just needs a timestamp *at least* that large.  The current time will
work.  Cassandra needs this to ensure that you are not removing
later-added data.

Client 1 sends node X: Add 'a' at 11:00:00
Client 2 sends node Y: Remove 'a' at 11:00:01
Client 3 sends node Z: Add 'a' at 11:00:02

In this scenario, the final update to 'a' is what the system will
eventually see as the state.  If there were no timestamps, it would be
a race to see which of the changes prevailed.  With the timestamps,
the original 'a' that 1 added is removed by 2, and 3's changes are


On Sun, Nov 8, 2009 at 10:57 PM, Ramzi Rabah <> wrote:
> Hello all:
> I am confused about the need of passing a  timestamp for the remove
> operation. Why does the remove operation in Cassandra require a
> timestamp? What happens if I provide a remove call with a different
> timestamp than what I inserted, will the row still be deleted?
> Thanks
> Ray

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