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From AJ ...@dude.podzone.net>
Subject Re: Docs: "Why do deleted keys show up during range scans?"
Date Mon, 13 Jun 2011 16:09:24 GMT
On 6/13/2011 9:25 AM, Stephen Connolly wrote:
> On 13 June 2011 16:14, AJ<aj@dude.podzone.net>  wrote:
>> On 6/13/2011 7:03 AM, Stephen Connolly wrote:
>>> 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?
>> I would expect it to not return anything (no row at all) for both of those
>> cases.  Are you saying that an empty row is returned for rows that do not
>> match the predicate?  So, if I perform a range slice where the range is
>> every row of the CF and the slice equates to no matches and I have 1 million
>> rows in the CF, then I will get a result set of 1 million empty rows?
>>
> No I am saying that for each row that matches, you will get a result,
> even if the columns that you request happen to be empty for that
> specific row.
>

Ok, this I understand I guess.  If I query a range of rows and want only 
a certain column and a row does not have that column, I would like to 
know that.

> Likewise, any deleted rows in the same row range will show as empty
> because C* would have a tone of work to figure out the difference
> between being deleted and being empty.
>

But, if a row does indeed have the column, but that row was deleted, why 
would I get an empty row?  You say because of a ton of work.  So, the 
tombstone for the row is not stored "close-by" for quick access... or 
something like that?  At any rate, how do I figure out if the empty row 
is empty because it was deleted?  Sorry if I'm being dense.



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