I created external table in Hive from Oracle table using JDBCStorageHandler. Queries are slow and when I look at plan given by explain command it says "Plan not optimized by CBO".
I tried everything that I could thing off, building statistics, setting different kinds of parameters in Hive, but it just doesn't change anything.
What is interesting is when I created external table from Postgres, queries are super fast and plans are cost based optimized.
Can somebody tell me if there is maybe some one going work on this issue? Is there some specific configuration to make it work on Oracle?
Hive version is 3.0, Oracle version is 12c and I tried both with ojdbc6 and ojdbc7.
Thank you for your help.