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From Alexander Paschenko <alexander.a.pasche...@gmail.com>
Subject Re: DML data streaming
Date Wed, 08 Feb 2017 15:44:43 GMT
Also, currently it's possible to run SELECTs on "streamed"
connections, and probably this is odd and should not be released too,
what do you think?

- Alex

2017-02-08 18:00 GMT+03:00 Alexander Paschenko
<alexander.a.paschenko@gmail.com>:
> Hello Igniters,
>
> I'd like to raise few questions regarding data streaming via DML statements.
>
> Currently, all types of DML statements are supported (INSERT, UPDATE,
> DELETE, MERGE).
>
> UPDATE and DELETE are supported in streaming mode only when their
> WHERE condition is bounded with _key and/or _val columns, and UPDATE
> works only for _val column directly.
>
> Seeing some activity in direction of hiding _key and _val from the
> user as far as possible, these features seem pointless and should not
> be released, what do you think?
>
> Also INSERT in streaming mode currently does not throw errors on
> duplicate keys and silently ignores such new records (as long as it's
> faster than it would work if we'd introduced receiver that would throw
> exceptions) - this can be fixed with additional flag that could
> _optionally_ make INSERT slower but more accurate in semantic.
>
> And MERGE in streaming mode currently not totally accurate in
> semantic, too - on key presence, it will just replace whole value with
> new one thus potentially making values of some concrete columns/fields
> lost - this is analogous to
> https://issues.apache.org/jira/browse/IGNITE-4489, but hardly can be
> fixed as long as probably it would hit performance and would be
> unresonably complex to implement.
>
> I suggest that we drop all except INSERT and introduce optional flag
> for its totally correct semantic behavior as described above.
>
> - Alex

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