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From Yuta Morisawa <yu-moris...@kddi-research.jp>
Subject Re: Some question about document
Date Thu, 12 Jul 2018 01:55:13 GMT
Thank you for your answer.

 > For POJOs Flink has a custom serializer. For arbitrary objects we use
 > kryo, and can use Avro as a fallback.
https://ci.apache.org/projects/flink/flink-docs-release-1.5/dev/types_serialization.html#serialization-of-pojo-types

It may be the reverse.
Kryo is for fallback, right?


On 2018/07/11 19:00, Chesnay Schepler wrote:
> 1) TypeInformation are used to create serializers, comparators and to 
> verify correctness of certain operations (like projections on tuple 
> datasets).
> 
> 2) see 
> https://flink.apache.org/news/2015/05/11/Juggling-with-Bits-and-Bytes.html
> 
> 3) Flink comes with a number of serializers for varying types as 
> outlined here 
> <https://ci.apache.org/projects/flink/flink-docs-release-1.5/dev/types_serialization.html#flinks-typeinformation-class>.
> For POJOs Flink has a custom serializer. For arbitrary objects we use 
> kryo, and can use Avro as a fallback.
> 
> On 11.07.2018 09:24, Yuta Morisawa wrote:
>> Hi all
>>
>> Now, I'm reading Flink document and I have some points to feel 
>> difficult to get an idea.
>> I'd appreciate if you tell it me.
>>
>> 1,TypeInformation
>>  I understand TypeInformation is used for selecting relevant 
>> serializer and comparator.
>>  But, the ducument doesn't specify if it has another way to be used.
>>
>>  So, what I want to know is that what kinds of process gets benefit 
>> from TypeInformation other than serializer and comparator.
>>
>> 2, Managed Memory
>>  The word "Managed memory" is appeared several time in the document 
>> but I can't find any detail description.
>>  This is the only document I found 
>> (https://www.slideshare.net/sbaltagi/overview-of-apacheflinkbyslimbaltagi)
>>
>>  If anyone has document that explains managed memory, please let me know.
>>
>> 3, Serializer
>>  What do the words in the document  "serializers we ship with Flink" 
>> mean? I know Flink uses avro for POJOs, is it the same thing?
>> https://ci.apache.org/projects/flink/flink-docs-release-1.5/dev/types_serialization.html

>>
>>
>>
>> Regards,
>> Yuta
>>
> 


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