This is placeholder body text for a future post on Oracle partition pruning. It will eventually cover how the cost-based optimizer eliminates partitions at parse time versus execution time, and why bind variables can quietly disable pruning that looked fine in a trace.
A second section will likely walk through a real execution plan, pointing out the PARTITION RANGE step and how to tell from KEY(SUBQUERY) labeling whether pruning happened as expected.
The closing section will probably cover monitoring: what to watch for in AWR reports when pruning silently stops working after a statistics refresh or an application change.