Automated Physical Designers: What You See is (Not) What You Get
The explosion of available data in the last few years has in-creased the importance of physical database design, since the selection of proper physical structures (e.g. indices, partitions and materialized views) may improve query execution performance by several orders of magnitude. Commercial DBMS vendors have recognized this need and offered automated physical design tools as part of their products. These tools use what-if interfaces to simulate the presence of different physical structures and recommend physical designs that minimize the estimated execution time of a given workload. Along with the recommended design, they deliver an estimation of the expected improvement the new design brings.