after you run such query, check out the KYLIN_HOME/logs/kylin.log, there should be snippet like:
2016-08-04 00:48:31,990 INFO [http-bio-7070-exec-7] service.QueryService:399 : Scan count for each storageContext: 12306477, 2016-08-04 00:48:31,991 INFO [http-bio-7070-exec-7] controller.QueryController:197 : Stats of SQL response: isException: false, duration: 56152, total scan count 12306477 2016-08-04 00:48:32,000 WARN [http-bio-7070-exec-7] can you let us know " Scan count for each storageContext" and the size of your query result? On Thu, Aug 4, 2016 at 2:21 PM, Li Yang <[email protected]> wrote: > Depending on how many rows and how many count distinct values are > returned, the query may take much memory and become slow. > > By saying querying uv of a month data, how many rows do you expect? Also > what's the precision of the HLL measure? Lower the precision can ease the > problem too. > > On Fri, Jul 29, 2016 at 4:54 PM, 张天生 <[email protected]> wrote: > >> I'm using kylin 1.5.2.1. I built a cube for a month's event data of >> advertisment impression/click/conversion. It consists of 6 dimensions and 8 >> measures. It consists of 2 uv measures, and uv measure was computed by >> DISTINCT COUNT. The cube size is 2G. When i queried uv measures of a month >> data, the memory quickly increased to 30G+, and the quey was also slowly. I >> don't known why it occupied so much memory, but cube size is only 2G, >> memory data expanded so big. Hower, when i executed simple silimar sum or >> count query ,it was fast and occupied memory not too much. >> > > -- Regards, *Bin Mahone | 马洪宾*
