Guides
Meta Table Functions
DuckDB has the following built-in table functions to obtain metadata about available catalog objects:  
* [`duckdb_columns()`](#docs:sql:meta:duckdb_table_functions::duckdb_columns): columns
* [`duckdb_constraints()`](#docs:sql:meta:duckdb_table_functions::duckdb_constraints): constraints
* [`duckdb_databases()`](#docs:sql:meta:duckdb_table_functions::duckdb_databases): lists the databases that are accessible from within the current DuckDB process
* [`duckdb_dependencies()`](#docs:sql:meta:duckdb_table_functions::duckdb_dependencies): dependencies between objects
* [`duckdb_extensions()`](#docs:sql:meta:duckdb_table_functions::duckdb_extensions): extensions
* [`duckdb_functions()`](#docs:sql:meta:duckdb_table_functions::duckdb_functions): functions
* [`duckdb_indexes()`](#docs:sql:meta:duckdb_table_functions::duckdb_indexes): secondary indexes
* [`duckdb_keywords()`](#docs:sql:meta:duckdb_table_functions::duckdb_keywords): DuckDB's keywords and reserved words
* [`duckdb_optimizers()`](#docs:sql:meta:duckdb_table_functions::duckdb_optimizers): the available optimization rules in the DuckDB instance
* [`duckdb_schemas()`](#docs:sql:meta:duckdb_table_functions::duckdb_schemas): schemas
* [`duckdb_sequences()`](#docs:sql:meta:duckdb_table_functions::duckdb_sequences): sequences
* [`duckdb_settings()`](#docs:sql:meta:duckdb_table_functions::duckdb_settings): settings
* [`duckdb_tables()`](#docs:sql:meta:duckdb_table_functions::duckdb_tables): base tables
* [`duckdb_types()`](#docs:sql:meta:duckdb_table_functions::duckdb_types): data types
* [`duckdb_views()`](#docs:sql:meta:duckdb_table_functions::duckdb_views): views
* [`duckdb_temporary_files()`](#docs:sql:meta:duckdb_table_functions::duckdb_temporary_files): the temporary files DuckDB has written to disk, to offload data from memory