I have a dimension user_tags, it is a multi-value column, for example the
value is "1_3_12_15_27_35_...", it was seperated by "_". As i known, kylin
don't directly propress this multi-value column, it must preprocess it to a
single value column, but it will increase record count to 50~100 times, the
data is too big.So is there a way to deal with multi-value dimension, it
don't need to split the value to many record, in calculate dimension
cardinality, it can read original data and automate split the value to
multi-value and process, and it will save disk i/o and cpu spending.
