This dataset presents benchmark data for the SIGMOD 2025 publication "An Elephant Under the Microscope: Analyzing the Interaction of Optimizer Components in PostgreSQL" (https://doi.org/10.1145/3709659). The dataset spans multiple different experiments, each analyzing how different components of relational query optimizers influence each other and how they perform when faced with faulty input. For each experiment a dedicated ZIP file is available. These files contain READMEs with technical information (e.g. table columns). Detailed descriptions of the individual experiments can be found in the actual publication, as well as in the code repository that provides the actual experiment scripts for reproducibility (available at https://github.com/db-tu-dresden/SIGMOD25-PostgreEval).