The preconditions is, the candidate cubes need match with SQL query, including join conditions (inner, left), dimension, measures; If more than 1 cubes match the condition, Kylin will select the most efficient one, for example: Cube A has 10 dimensions, Cube B has 20 dimensions, use A;
On 6/14/15, 6:53 PM, "Vineet Mishra" <[email protected]> wrote: >Hi Shi, > >Wanted to know how "Kylin will pick the ³best matched² one (with a set of >rules)" and moreover why does cube build job runs with single M/R job. Is >it really necessary to have single mapper and reducer job or it can be >tweaked as well, because the cube creation takes hell lot of time, around >2:30 hrs which is really too much in future when the data grows! > >It there any work around to make the M/R to spawn multiple tasks to >expedite the running process? > >Thanks! > >On Fri, Jun 12, 2015 at 12:49 PM, Shi, Shaofeng <[email protected]> wrote: > >> Only 1 cube will be picked up to server a query; If you have multiple >> active cubes with the same source table, Kylin will pick the ³best >> matched² one (with a set of rules); You can get the info in kylin.logs; >> for example: >> >> QueryRouter.findBestMatchCube(QueryRouter.java:146)] - Find candidates >>by >> table Š cube1, cube2, ... >> Š. Exclude cube2 as ... >> findBestMatchCube(QueryRouter.java:185)] - Use weak matched cube cube1 >> >> If you have preference on a certain cube, you can disable others, only >> leave the preferred as ³active², then it will be the only one to server >> SQL queries; >> >> On 6/12/15, 3:05 PM, "Vineet Mishra" <[email protected]> wrote: >> >> >Hi All, >> > >> >I was curious to know as when I am created multiple cubes for the same >> >table as source and later I am referring the cube to get the cube data. >> > >> >Which table will it refer since our reference is still limited to >>source >> >table but the query is made from hbase table. So I wanted to have the >> >understanding as how/what changes need to be done so as to assure the >> >multiple cubes are formed and queries for the same table. >> > >> >Urgent Call! >> > >> >Thanks! >> >>
