Keynote Talk and Tutorials -- Knowledge Engineering in the Era of Artificial Intelligence -- Causality, Attribution-Scores and Repairs in Databases -- When operations research meets databases -- Query Processing and Data Exploration -- Using a Key-Value Index-Store for Cross-Model Join Queries Over Heterogeneous Data Sources -- Reconstructing Spatiotemporal Data with C-VAEs -- What Happens when Two Multi-Query Optimization Paradigms Combine -- Skyline-Based Temporal Graph Exploration -- Temporal Graph Processing in Modern Memory Hierarchies -- Data Science and Fairness -- Comparing and Improving Active Learning Uncertainty Measures for Transformer Models -- FARMUR: Fair Adversarial Retraining to Mitigate Unfairness in Robustness -- Exploring Heterogeneous Data Graphs Through their Entity Paths -- Managing Linked Nulls in Property Graphs: Tools to Ensure Consistency and Reduce Redundancy -- Assessment of Data Quality in a Data Lakehouse Through Multi-Granularity Data Profiling -- Data Ingestion Validation through Stable Conditional Metrics with Ranking and Filtering -- An Ontology for Representing and Querying Semantic Trajectories in the Maritime Domain -- Extracting Provenance of Machine Learning Experiment Pipeline Artifacts. .

This book constitutes the proceedings of the 27th European Conference on Advances in Databases and Information Systems, ADBIS 2023, held in Barcelona, Spain, during September 4-7, 2023. The 11 full papers presented in this book together with 3 keynotes and tutorials were carefully reviewed and selected from 77 submissions. The papers are organized in the following topical sections: keynote talk and tutorials; query processing and data exploration, data science and fairness and Data and Metadata Quality.