Information Schema
Version 0.4.0

The views in the information_schema are SQL-standard views that describe the catalog entries of the database. These views can be filtered to obtain information about a specific column or table.

Database, Catalog and Schema

The top level catalog view is information_schema.schemata. It lists the catalogs and the schemas present in the database and has the following layout:

Column Description Type Example
catalog_name Name of the database that the schema is contained in. Not yet implemented. VARCHAR NULL
schema_name Name of the schema. VARCHAR 'main'
schema_owner Name of the owner of the schema. Not yet implemented. VARCHAR NULL
default_character_set_catalog Applies to a feature not available in DuckDB. VARCHAR NULL
default_character_set_schema Applies to a feature not available in DuckDB. VARCHAR NULL
default_character_set_name Applies to a feature not available in DuckDB. VARCHAR NULL
sql_path The file system location of the database. Currently unimplemented. VARCHAR NULL

Tables and Views

The view that describes the catalog information for tables and views is information_schema.tables. It lists the tables present in the database and has the following layout:

Column Description Type Example
table_catalog The catalog the table or view belongs to. Not yet implemented. VARCHAR NULL
table_schema The schema the table or view belongs to. VARCHAR 'main'
table_name The name of the table or view. VARCHAR 'widgets'
table_type The type of table. One of: BASE TABLE, LOCAL TEMPORARY, VIEW. VARCHAR 'BASE TABLE'
self_referencing_column_name Applies to a feature not available in DuckDB. VARCHAR NULL
reference_generation Applies to a feature not available in DuckDB. VARCHAR NULL
user_defined_type_catalog If the table is a typed table, the name of the database that contains the underlying data type (always the current database), else null. Currently unimplemented. VARCHAR NULL
user_defined_type_schema If the table is a typed table, the name of the schema that contains the underlying data type, else null. Currently unimplemented. VARCHAR NULL
user_defined_type_name If the table is a typed table, the name of the underlying data type, else null. Currently unimplemented. VARCHAR NULL
is_insertable_into YES if the table is insertable into, NO if not (Base tables are always insertable into, views not necessarily.) VARCHAR 'YES'
is_typed YES if the table is a typed table, NO if not. VARCHAR 'NO'
commit_action Not yet implemented. VARCHAR 'NO'

Columns

The view that describes the catalog information for columns is information_schema.columns. It lists the column present in the database and has the following layout:

Column Description Type Example
table_catalog Name of the database containing the table. Not yet implemented. VARCHAR NULL
table_schema Name of the schema containing the table. VARCHAR 'main'
table_name Name of the table. VARCHAR 'widgets'
column_name Name of the column. VARCHAR 'price'
ordinal_position Ordinal position of the column within the table (count starts at 1). INTEGER 5
column_default Default expression of the column. VARCHAR 1.99
is_nullable YES if the column is possibly nullable, NO if it is known not nullable. VARCHAR 'YES'
data_type Data type of the column. VARCHAR 'DECIMAL(18,2)'
character_maximum_length If data_type identifies a character or bit string type, the declared maximum length; null for all other data types or if no maximum length was declared. INTEGER 255
character_octet_length If data_type identifies a character type, the maximum possible length in octets (bytes) of a datum; null for all other data types. The maximum octet length depends on the declared character maximum length (see above) and the character encoding. INTEGER 1073741824
numeric_precision If data_type identifies a numeric type, this column contains the (declared or implicit) precision of the type for this column. The precision indicates the number of significant digits. For all other data types, this column is null. INTEGER 18
numeric_scale If data_type identifies a numeric type, this column contains the (declared or implicit) scale of the type for this column. The precision indicates the number of significant digits. For all other data types, this column is null. INTEGER 2
datetime_precision If data_type identifies a date, time, timestamp, or interval type, this column contains the (declared or implicit) fractional seconds precision of the type for this column, that is, the number of decimal digits maintained following the decimal point in the seconds value. No fractional seconds are currently supported in DuckDB. For all other data types, this column is null. INTEGER 0

Catalog Functions

Several functions are also provided to see details about the schemas that are configured in the database.

Function Description Example Result
current_schema() Return the name of the currently active schema. Default is main. current_schema() 'main'
current_schemas(boolean) Return list of schemas. Pass a parameter of True to include implicit schemas. current_schemas(true) ['temp', 'main', 'pg_catalog']