An insert or update statement that is taking a long time to complete is often working on the indexes belonging to the table rather than the table itself. If you look at the plan and finds nothing wrong, it is easy to forget that the indexes have to be updated as well.
Øyvind's Blog
Enesi Consulting AS
Trust your data
About
Enesi Consulting AS is at the time being just Øyvind Isene. Mostly Oracle, Linux, integration, and troubleshooting.
Learn More