Hi Tracy,

Ignite support SQLFieldQuery  for the purpose[1]
SQL with default marshaller (Binary) will be use only needed fields when
evaluation.

[1]: https://apacheignite.readme.io/docs/sql-queries#fields-queries

On Mon, Oct 10, 2016 at 8:54 PM, Tracy Liang (BLOOMBERG/ 731 LEX) <
tlian...@bloomberg.net> wrote:

> Thanks for this clear explanation, Alexey. Basically I want to use Ignite
> as a shared in-memory layer among multiple Spark Server instances. Also I
> have another question: does ignite cache support predicate pushdown or a
> logic view of cache? For example, I only want certain column of the value
> instead of returning the entire universe. How do I do that?
>
>
> From: user@ignite.apache.org
> Subject: Re: Is it possible to enable both REPLICATED and PARTITIONED?
>
> Tracy,
>
> First of all, cache mode and number of backups could be set only once - on
> cache start.
> So, if you know the size of your cluster you could set number of backups
> before cache start.
> But, I think it is not reasonable to set number of backups equals to
> number of nodes.
> If you need 100% high availability, just use replicated cache. But I would
> recommend to think about how many nodes at once can be lost?
> May be it is reasonable to set backups = 2? The more backups you choose -
> the more memory will be consumed by backup partitions and also
> grid will spend time in rebalancing data.
> What is your use case?
>
>
> On Mon, Oct 10, 2016 at 11:18 PM, Tracy Liang (BLOOMBERG/ 731 LEX) <
> tlian...@bloomberg.net> wrote:
>
>> Thanks, and PARTITIONED mode could have any number of backups right? I
>> want backups for high availability and also my dataset is large. I guess I
>> will use PARTITIONED mode and configure number of backups based on actual
>> needs in that case right?
>>
>> From: user@ignite.apache.org
>> Subject: Re: Is it possible to enable both REPLICATED and PARTITIONED?
>>
>> Hi, Tracyl.
>>
>> Actually, REPLICATED cache is a PARTITIONED cache win backups on all
>> nodes.
>>
>> But, why did you need  this?
>>
>> On Mon, Oct 10, 2016 at 10:46 AM, Tracyl <tlian...@bloomberg.net> wrote:
>>
>>> As subject shows.
>>>
>>>
>>>
>>> --
>>> View this message in context: http://apache-ignite-users.
>>> 70518.x6.nabble.com/Is-it-possible-to-enable-both-
>>> REPLICATED-and-PARTITIONED-tp8167.html
>>> Sent from the Apache Ignite Users mailing list archive at Nabble.com.
>>>
>>
>>
>>
>> --
>> Alexey Kuznetsov
>>
>>
>>
>
>
> --
> Alexey Kuznetsov
>
>
>


-- 
Vladislav Pyatkov

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