  Virtual Knowledge Graphs (VKG) constitute one of the most promising paradigms
for integrating and accessing legacy data sources. A critical bottleneck in the
integration process involves the definition, validation, and maintenance of
mappings that link data sources to a domain ontology. To support the management
of mappings throughout their entire lifecycle, we propose a comprehensive
catalog of sophisticated mapping patterns that emerge when linking databases to
ontologies. To do so, we build on well-established methodologies and patterns
studied in data management, data analysis, and conceptual modeling. These are
extended and refined through the analysis of concrete VKG benchmarks and
real-world use cases, and considering the inherent impedance mismatch between
data sources and ontologies. We validate our catalog on the considered VKG
scenarios, showing that it covers the vast majority of patterns present
therein.
