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From Sylvain Lebresne <sylv...@datastax.com>
Subject Re: CQL 3.0 - UPDATE Statement - how it works?
Date Wed, 25 Apr 2012 12:05:01 GMT
In CQL, both UPDATE AND INSERT have the same semantic and are both "upsert".
I.e, INSERT does not fail if the record was already existing and
UPDATE does not fail if the record wasn't existing.

--
Sylvain

On Wed, Apr 25, 2012 at 1:18 PM, Maciej Miklas
<mac.miklas@googlemail.com> wrote:
> CQL will have UPDATE future, I am trying to understand how this could work.
>
> Every write is an append to SSTable, UPDATE would need to change data, but
> only if it exists, and this is problematic, since we have distributed
> system.
>
> Is UPDATE special kind of insert, which changes given data only if it
> already exists? Will be UPDATE resolved first during read operation (SSTable
> merge)?
>
>
> Thanks,
> Maciej

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