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From Kostas Kloudas <k.klou...@data-artisans.com>
Subject Re: ListState to List
Date Thu, 18 May 2017 09:48:32 GMT
Hi Radu,

Why not using a ValueState that inside stored the whole list. 
Whenever you state#get() you get the whole list and you can sort it.

> On May 18, 2017, at 3:31 AM, Radu Tudoran <radu.tudoran@huawei.com> wrote:
> Hi Aljoscha,
> Thanks for the clarification. I understand that there might be advantages in some cases
not to have the List-like interface, while in other scenarios (like the one I described there
aren't). Considering this, why not having 2 type of states: ListState and StreamInListState
- users would use the one it is more appropriate. What do you think?
> -----Original Message-----
> From: Aljoscha Krettek [mailto:aljoscha@apache.org] 
> Sent: Thursday, May 18, 2017 12:15 AM
> To: dev@flink.apache.org
> Subject: Re: ListState to List
> Hi,
> The interface is restrictive on purpose because depending on the state backend it might
not be possible to provide a List-like interface. There might be state backends that stream
in the list from somewhere else or other restrictions. If we now allowed a more general interface
here we would possibly prevent optimisations in the future or make certain implementations
very hard to to efficiently.
> Best,
> Aljoscha
>> On 16. May 2017, at 21:56, Radu Tudoran <radu.tudoran@huawei.com> wrote:
>> Hi,
>> I would like to work with ListState, more specifically I would need to access the
contents and sort them. For this I would need a collection type (e.g., the List, Array...).
>> However, I see that if I have a variable of type <<ListState state=..>>
the only interfaces I have are:
>> state.get -> which returns an Iterable Or state.get.getIterator which 
>> returns an Iterator
>> Basically if I use any of these I need now to copy the contents in an actual List
of Array.  Is there any way to avoid this? ..perhaps there is an implicit type that I can
convert to...

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