We demonstrate the most important new feature of SQL:2023, namely SQL/PGQ, which eases
querying graphs using SQL by introducing new syntax for pattern matching and (shortest)
path-finding. We show how support for SQL/PGQ can be integrated into an RDBMS, specifically
in the DuckDB system, using an extension module called DuckPGQ. As such, we also demonstrate
the use of the DuckDB extensibility mechanism, which allows us to add new functions,
data types, operators, optimizer rules, storage systems, and even parsers to DuckDB.
We also describe the new data structures and algorithms that the DuckPGQ module is
based on, and how they are injected into SQL plans.
