it means, ignite is not useful for such usecases ? correct ? On 7 February 2017 at 19:27, Andrey Mashenkov <andrey.mashen...@gmail.com> wrote:
> Hi Anil, > > It looks like "collocate=true" can be set on per JdbcConnection basis > only, via "ignite.jdbc.collocation" property. > > > On Tue, Feb 7, 2017 at 3:24 PM, Anil <anilk...@gmail.com> wrote: > >> Hi Andrey, >> >> its clear now. is there any way to achieve group by results of collocate >> = false with jdbc client of collocate = true. i mean to change collocate >> for each query ? >> >> i have to use collocate = true for join of two caches and have only one >> jdbc client node. >> >> Thanks. >> >> On 7 February 2017 at 17:47, Andrey Mashenkov <andrey.mashen...@gmail.com >> > wrote: >> >>> Hi Anil, >>> >>> If you have GroupBy condition in query and all "rows" that belong to one >>> group are collocated with affinity key, then group is collocated and you >>> can use "collocate = true" option to allow Ignite apply optimization. >>> Otherwise, it is not a collocated grouping and GroupBy should be apply >>> on reduce stage; You will get wrong result with "collocate = true" option. >>> >>> Map response is always returned to node that initiate query (reduce >>> node), reduce stage will apply anyway. >>> >>> >>> On Tue, Feb 7, 2017 at 1:37 PM, Anil <anilk...@gmail.com> wrote: >>> >>>> Hi Andrey, >>>> >>>> thanks for response and little confused. >>>> >>>> I hope "group" is the entries of two (or more) caches which are >>>> collocated with affinity key. please correct if i am wrong. >>>> >>>> "For example: In this case, we can make grouping and apply Having >>>> condition on map stage, that >>>> results in reducing network traffic." - *Agree. no aggregation in >>>> reduce and apply pagination and return to client ? or just return map >>>> response to client ?* >>>> >>>> Thanks. >>>> >>>> >>>> On 7 February 2017 at 14:55, Andrey Mashenkov < >>>> andrey.mashen...@gmail.com> wrote: >>>> >>>>> Hi Anil, >>>>> >>>>> Group by queries with collocate = true will be correct if: >>>>> for every group there is only partition that contains all data of this >>>>> group. >>>>> Ignite does not know if group data is collocated for a query, so with >>>>> this option we can give a hint to Ignite. >>>>> >>>>> For example: In this case, we can make grouping and apply Having >>>>> condition on map stage, that >>>>> results in reducing network traffic. >>>>> >>>>> For non-collocated groups we can't apply Having on map stage as we >>>>> have only part of data at this time. >>>>> So, in this case with collocate = true we can get wrong results. >>>>> >>>>> >>>>> >>>>> On Tue, Feb 7, 2017 at 6:29 AM, Anil <anilk...@gmail.com> wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> May I know what do you mean by "When used incorrectly" ? >>>>>> >>>>>> group by queries with collocate = true is not incorrect usage or i >>>>>> misunderstood this ? >>>>>> >>>>>> Thanks. >>>>>> >>>>>> On 7 February 2017 at 01:26, vkulichenko < >>>>>> valentin.kuliche...@gmail.com> wrote: >>>>>> >>>>>>> Well, I would agree that the flag is confusing, but your >>>>>>> understanding is not >>>>>>> correct. When used incorrectly, this flag does breaks query result >>>>>>> because >>>>>>> it forces Ignite to change execution plan to more optimal. This >>>>>>> optimization >>>>>>> doesn't always work though (that's actually the reason why it's >>>>>>> configurable). >>>>>>> >>>>>>> -Val >>>>>>> >>>>>>> >>>>>>> >>>>>>> -- >>>>>>> View this message in context: http://apache-ignite-users.705 >>>>>>> 18.x6.nabble.com/NOT-IN-in-ignite-tp9861p10458.html >>>>>>> Sent from the Apache Ignite Users mailing list archive at Nabble.com. >>>>>>> >>>>>> >>>>>> >>>>> >>>>> >>>>> -- >>>>> Best regards, >>>>> Andrey V. Mashenkov >>>>> >>>> >>>> >>> >>> >>> -- >>> Best regards, >>> Andrey V. Mashenkov >>> >> >> > > > -- > Best regards, > Andrey V. Mashenkov >
