Hybrid Columnar Compression (HCC) in Oracle Exadata is a prime example of how physical infrastructure can significantly enhance the efficiency of data management and analysis—when used correctly. This is an area that also affects developers and data engineers: what it is, how it works, and what to expect. If HCC is used in your project, then everyone on the team should be aware of it, including the specifics of what, where, and how it is implemented. Otherwise, there may be a few surprises, as in the example I encountered recently: instead of achieving the expected storage savings and improved performance, there was a huge increase in space consumption, along with negative performance effects. Read on to find out what happened.