What’s in a name :
High Performance Analytics(HPA) became Business Intelligence Accelerator(BIA) which became Business Warehouse Accelerator(BWA) which will, eventually, become Open Database Analytics(ODA).

Anyway: After you’ve enabled a cube to be indexed/loaded to the BWA, all queries belonging to that cube will be executed via the BWA. You’re able to exclude a particular query, belonging to a “BWA-cube”, to be ran via the BWA.
Find the query which shouldn’t use the BWA via SE16 and table RSRREPDIR.
Within table RSRREPDIR, set field NOHPA (=Do Not Use HPA Index) to ‘X’ and save the change. From now onwards, the particular query will not use the BWA eventhough the cube it “runs” on is BWA enabled.