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From David Boxenhorn <da...@citypath.com>
Subject Re: Why do Digest Queries return hash instead of timestamp?
Date Wed, 13 Jul 2011 11:13:43 GMT
How would you know which data is correct, if they both have the same
timestamp?

On Wed, Jul 13, 2011 at 12:40 PM, Boris Yen <yulinyen@gmail.com> wrote:

> I can only say, "data" does matter, that is why the developers use hash
> instead of timestamp. If hash value comes from other node is not a match, a
> read repair would perform. so that correct data can be returned.
>
>
> On Wed, Jul 13, 2011 at 5:08 PM, David Boxenhorn <david@citypath.com>wrote:
>
>> If you have to pieces of data that are different but have the same
>> timestamp, how can you resolve consistency?
>>
>> This is a pathological situation to begin with, why should you waste
>> effort to (not) solve it?
>>
>> On Wed, Jul 13, 2011 at 12:05 PM, Boris Yen <yulinyen@gmail.com> wrote:
>>
>>> I guess it is because the timestamp does not guarantee data consistency,
>>> but hash does.
>>>
>>> Boris
>>>
>>>
>>> On Wed, Jul 13, 2011 at 4:27 PM, David Boxenhorn <david@citypath.com>wrote:
>>>
>>>> I just saw this
>>>>
>>>> http://wiki.apache.org/cassandra/DigestQueries
>>>>
>>>> and I was wondering why it returns a hash of the data. Wouldn't it be
>>>> better and easier to return the timestamp? You don't really care what the
>>>> data is, you only care whether it is more or less recent than another piece
>>>> of data.
>>>>
>>>
>>>
>>
>

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