Rules for UPDATE, MERGE, and DELETE

You have two ways to specify parallel directives for UPDATE, MERGE, and DELETE operations (if PARALLEL DML mode is enabled):

• Use a parallel clause in the definition of the table being updated or deleted (the reference object).

• Use an update, merge, or delete parallel hint in the statement.

Parallel hints are placed immediately after the UPDATE, MERGE, or DELETE keywords in UPDATE, MERGE, and DELETE statements. The hint also applies to the underlying scan of the table being changed.

You can use the ALTER SESSION FORCE PARALLEL DML statement to override parallel clauses for subsequent UPDATE, MERGE, and DELETE statements in a session. Parallel hints in UPDATE, MERGE, and DELETE statements override the ALTER SESSION FORCE PARALLEL DML statement.

For possible limitations, see "Limitation on the Degree of Parallelism".