In most of the cases it only uses 1 column to persist the measure values; But sometimes it will split to multiple columns; You can get the information in Cube JSON file, in “hbase_mapping” part;
On 8/28/15, 11:17 AM, "steven zhang" <[email protected]> wrote: >Hi Meng, > >kylin have not use multiple columns store multiple measures just only F1:M >so kylin using "rowkey:dim1+dim2, value:sum1+","+count2+",”+sum3” as you >list > >Best regards > >Steven Zhang > >> On Aug 28, 2015, at 10:59 AM, [email protected] wrote: >> >> sorry about my poor english, what i means is: >> >> example: dim1,dim2,sum1,count2,sum3 >> >> will kylin store the aggr result like: >> rowkey:dim1+dim2,value:sum1 >> rowkey:dim1+dim2,value:count2 >> rowkey:dim1+dim2,value:sum3 >> >> or: >> rowkey:dim1+dim2, value:sum1+","+count2+","+sum3 >> >> the second way seem to save a lot of storage because it only store >>rowkey once; >> >> >> >> 中国移动广东有限公司 网管中心 梁猛 >> [email protected] >> >> 发件人： steven zhang >> 发送时间： 2015-08-28 10:33 >> 收件人： dev >> 主题： Re: one question, how kylin store data in hbase? >> Hi Meng, >> >> To my understanding: >> >> kylin using RowKey:=cuboid+dimensions RowValue:=measures(name+value) >> >> For example >> select class_id,sum(score) as total_score from student_score group by >>class_id >> >> 1.kylin will generate SQLDigest(include parameters) when execute sql >> >> 2.If the dimension index of class_id is 4 so the cuboid is 00010000 = >>16 ,cuboid length = 8 bytes “00100000" is the last byte and the rest of >>rowkey store the dimension value of class_id >> >> 3.How many rows is affected by numbers of dimensions . if dimensions >>numbers = 5 so the combination is 2^5 = 32 >> >> 4.Hbase scan range (startRowKey and stopRowKey). if group by >>dimension1,dimension2 (dimension1 index=7 , dimension2 index=5) so >>startRowKey = 0000000 96 00 stopRowKey = 0000000 96 FF0 >> and the measure value is after group by dimension1,dimension2 >>(high―>low) . calculate the item such as SUM(Price),Min(Price) etc. >> >> Best regards >> >> Steven Zhang >> >> >>> On Aug 28, 2015, at 9:20 AM, [email protected] wrote: >>> >>> for example，if i have 3 calculation item in cube, will kylin store >>>each dimention of calculations in 3 rows or only 1 row(and split it >>>when query)? >>> >>> >>> >>> >>> 中国移动广东有限公司 网管中心 梁猛 >>> [email protected] >> >
