By nbayliss-Oracle on May 26, 2015
Most of you will be familiar with the concept of direct path load and how it’s an efficient way to load large volumes of data into an Oracle database as well as being a great technique to use when moving and transforming data inside the database. It’s easy to use in conjunction with parallel execution too, so you can scale out and use multiple CPUs and database servers if you need to process more data in less time.
Probably less well known is how the Oracle database manages space during direct path load operations. This is understandable because the Oracle database uses a variety of approaches and it has not always been very obvious which one it has chosen. The good news is that Oracle Database 12c from version 18.104.22.168 onwards makes this information visible in the SQL execution plan and it is also possible to understand what’s happening inside earlier releases with a bit of help from this post and some scripts I’ve linked to at the end.