Per table write id implementation (
HIVE-18192) have introduced write ID per table and used write ID to name the delta/base files and also as primary key for each row.
Now, exchange partition have to move delta/base files across tables without changing the write ID which causes incorrect results.
Also, this exchange partition feature is there to support the use-case of atomic updates. But with ACID updates, we shall support atomic-updates and hence it makes sense to not support exchange partition for ACID and MM tables.
The qtest file mm_exchangepartition.q test results to be updated after this change.