Description
It is no secret that for high-performance ETL processes, not only queries but also write operations should be parallelized.
But when you make use of it, is it simply "switch on and forget"? What do you have to consider? Can it also have negative effects?
After a short reminder on how it works (including space management methods), some patterns are presented that have been noticed in several ETL review and tuning projects and help to find the answers to the following questions:
What is the interaction between PDML and partitioning of the target table? Can PDML lead to increased fragmentation of the tablespace? Can you control it? How does the Hint PQ_DISTRIBUTE help? Do indexes on the target table have any influence?