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Documentation
/ SQL
PEG Parser
DuckDB v1.5 shipped an experimental parser based on PEG (Parser Expression Grammars). The new parser enables better suggestions, improved error messages, and allows extensions to extend the grammar. The PEG parser is currently disabled by default but you can opt-in using:
CALL enable_peg_parser();
The PEG parser is already used for generating suggestions. You can cycle through the options using TAB.
animals_db D FROM ducks WHERE habitat IS
IS ISNULL ILIKE IN INTERSECT LIKE
We are planning to make the switch to the new parser in the DuckDB v2.0 release.
As a tradeoff, the parser has a slight performance overhead, however, this is in the range of milliseconds and is thus negligible for analytical queries. For more details on the rationale for using a PEG parser and benchmark results, please refer to the CIDR 2026 paper by Hannes Mühleisen and Mark Raasveldt, or their blog post summarizing the paper.
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