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From Alexander Paschenko <alexander.a.pasche...@gmail.com>
Subject Re: DML data streaming
Date Wed, 15 Feb 2017 22:41:29 GMT

Regarding INSERT semantics in JDBC DML streaming mode - I've left only
INSERTs supports as we'd agreed before.

However, current architecture of streaming related internals does not
give any clear way to intercept key duplicates and inform the user -
say, I can't just throw an exception from stream receiver (which is to
my knowledge the only place where we could filter erroneous keys) as
long as it will lead to whole batch remap and it's clearly not what we
want here.

Printing warning to log from the receiver is of little to no use as it
will happen on data nodes so the end user won't see anything.

What I've introduced for now is optional config param that turns on
allowOverwrite on the streamer used in DML operation.

Does anyone have any thoughts about what could/should be done
regarding informing user about key duplicates in streaming mode? Or
probably we should just let it be as it is now?


2017-02-15 23:42 GMT+03:00 Dmitriy Setrakyan <dsetrakyan@apache.org>:
> On Wed, Feb 15, 2017 at 4:28 AM, Vladimir Ozerov <vozerov@gridgain.com>
> wrote:
>> Ok, let's put aside current fields configuration, I'll create separate
>> thread for it. As far as _KEY and _VAL, proposed change is exactly about
>> mappings:
>> class QueryEntity {
>>     ...
>>     String keyFieldName;
>>     String valFieldName;
>>     ...
>> }
>> The key thing is that we will not require users to be aware of our system
>> columns. Normally user should not bother about existence of hidden _KEY and
>> _VAL columns. Instead, we just allow them to optionally reference the whole
>> key and/or val through predefined name.
> Vladimir, how will it work from the DDL perspective. Let's say whenever
> user wants to create a table in Ignite?

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