This book constitutes the refereed proceedings of the 9th International Symposium on From Data Models and Back, DataMod 2020, held virtually, in October 2020.

The 11 full papers and 3 short papers presented in this book were selected from 19 submissions. The papers are grouped in these topical sections: machine learning;

Synthesis and Pruning as a Dynamic Compression Strategy for Efficient Deep Neural Networks.- Exploring Graph-Based Neural Networks for Automatic Brain Tumor Segmentation.- STDI-Net: Spatial-Temporal Network with Dynamic Interval Mapping for Bike Sharing Demand Prediction.- A Simulation-Based Approach for the Behavioural Analysis of Cancer Pathways.- Discovering the Impact of Notifications on Social Network Addiction.- A Simulation Study on Demand Disruptions and Limited Resources for Healthcare Provision.- A Formal Model for Emulating the Generation of Human Knowledge in Semantic Memory.- Analysis of COVID-19 data with PRISM: Parameter Estimation and SIR Modelling.- A Formal Model for the Simulation and Analysis of Early Biofilm Formation.- Query Rewriting On Path Views Without Integrity Constraints.- Evaluating Trace Encoding Methods in Process Mining.- Semantic Annotations in Clinical Guidelines.- Deriving Performance Measures of Workflow in Radiation Therapy from Real-Time Data.-Handshape Classification in a Reverse Dictionary of Sign Languages for the Deaf.