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From Stephen Connolly <stephen.alan.conno...@gmail.com>
Subject Re: Docs: "Why do deleted keys show up during range scans?"
Date Mon, 13 Jun 2011 13:03:45 GMT
It returns the set of columns for the set of rows... how do you
determine the difference between a completely empty row and a row that
just does not have any of the matching columns?

Well the answer is that Cassandra does not go and check whether there
are any columns outside of the range you are querying, so it will just
return the empty (for the column range you specified) row.... your
code needs to be robust enough to be able to understand that an empty
list of columns does not imply that there are no columns at all for
that row key (i.e. it is deleted and waiting tombstone expiry & gc) or
there is a column outside the range you queried.

On 13 June 2011 13:59, AJ <aj@dude.podzone.net> wrote:
> http://wiki.apache.org/cassandra/FAQ#range_ghosts
>
> "So to special case leaving out result entries for deletions, we would have
> to check the entire rest of the row to make sure there is no undeleted data
> anywhere else either (in which case leaving the key out would be an error)."
>
> The above doesn't read well and I don't get it.  Can anyone rephrase it or
> elaborate?
>
> Thanks!
>

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