Dear All, We are troubleshooting slow queries in our Kylin deployment, and we suspect that the issue is not with the cube definitions, but with our queries. At least we have some quite complex queries with a lot of range checks on dimension values, and we have observed different response times by changing the queries to alternative, but functionally equivalent ones.
Although it's hard to come to conclusions because we see a large variance in query response times (for the same query in the same environment, at roughly the same time). We have disabled query caching in kylin.properties (kylin.query.cache-enabled=false) to be able to have more conclusive results on what effect certain changes have on query execution time, but we still observe variance in query results on an environment that otherwise has no load. Perhaps this is due to caching within HBase or within the streaming receiver. Do you have any guidelines, best practices, documentation on how to tune queries for Kylin? (I'm aware of some cube tuning guidelines from the Kylin documentation, but now I'm looking for advice specifically about query optimization.) Many thanks, Andras
