Hi,
I have read in the doc that:
The following example forces the statement to use Oracle Database 11g Release 1 (11.1) behavior:
SELECT /*+ parallel(manual) */ ename, dname FROM emp e, dept d
WHERE e.deptno=d.deptno;
How Parallel Execution Works
Assuming auto DOP is enabled for the database instance, if we specify parallel(MANUAL) for the query above,then auto DOP is disabled, as well as statement queuing and in-memory parallel execution, and it reverts the behaviour of parallel execution to what it was on Oracle 11.1 (release 1), right? But.. which behaviour? Will the above statement execute serially? As per the DOP, will be dictionary DOP for the objects accessed by the query be used to determine the statement DOP? Of course, if insufficient parallel slaves are available, I think the statement will be queued.
I did not found too much information about this behaviour, and the "parallel(manual)" hint
Thank you