Boolean 

Dynamic. Scope = ALTER SESSION. 

FALSE 

TRUE | FALSE 

Note: This parameter refers to parallel execution, not to Oracle Parallel Server. 

PARALLEL_BROADCAST_ENABLED lets you improve performance of hash and merge join operations in which a very large join result set is joined with a very small result set (size being measured in bytes, rather than number of rows).

When this parameter is set to TRUE, the optimizer can choose to copy all the source rows of the small result set and broadcast a copy to each parallel server that is processing some rows of the larger set.