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) < [email protected]> 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: [email protected] > 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) < > [email protected]> 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: [email protected] >> 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 <[email protected]> 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
