[ https://issues.apache.org/jira/browse/KYLIN-2800?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Billy Liu reassigned KYLIN-2800: -------------------------------- Assignee: zhengdong > All dictionaries should be built based on the flat hive table > ------------------------------------------------------------- > > Key: KYLIN-2800 > URL: https://issues.apache.org/jira/browse/KYLIN-2800 > Project: Kylin > Issue Type: Bug > Reporter: zhengdong > Assignee: zhengdong > Attachments: > 0001-KYLIN-2800-All-dictionaries-should-be-built-based-on.patch > > > After KYLIN-2457, we still got wrong query result sometimes after a merging > job finished. > Finally, we realize the root cause is that we always use lookup table as > source data to build dictionaries for FK columns. > However, incremental lookup table doesn't mean sequential and incremental PK. > If a new record inserted into the lookup table while its PK column does not > have the max value, ID numbers in the new dictionary could be changed for > those PK value larger than the newest one. What's more, using lookup table as > source data for FK column's dictionary may has performance advantage for > merging job, but also may encounter too big dictionary problem for large > lookup tables. And we must add some validation rules to ensure the PK value > sequential and incremental. > On the another hand, we could just unify using the flat hive table as data > source for all dictionaries. -- This message was sent by Atlassian JIRA (v6.4.14#64029)