Sorry, I just start to lean kylin
When I execute the sql select * from kylin_sales where price > 2
in default sample cube of kylin, it failed with the message
ERROR while executing SQL "select * from kylin_sales where price > 2 LIMIT 50000": Can't find any realization. Please confirm with providers SQL digest: fact table DEFAULT.KYLIN_SALES,group by [],filter on[DEFAULT.KYLIN_SALES.PRICE],with aggregates[].
anybody knows the reason? Thanks
Kylin is a MOLAP (multidimensional online analytical processing) engine. It divides columns into dimensions and measures, expects queries to filter by dimensions and return aggregated measures.
Your query select * from kylin_sales where price > 2
does not work, because price
is not a dimension thus is not suitable for filtering. Also the query does not select any aggregated measures.
A simple MOLAP query is like select week_beg_dt, sum(price) from kylin_sales where meta_categ_name='Collectibles' group by week_beg_dt
Kylin also supports a special type of RAW
measure, that allows filter such as price > 2
, but that's not demonstrated by the sample cube.