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; ???????????????????? ???????? ???? [email protected] ???????? steven zhang ?????????? 2015-08-28 10:33 ???????? dev ?????? 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)? > > > > > ???????????????????? ???????? ???? > [email protected]
