core.db_schema_to_pq

core.db_schema_to_pq(
    schema,
    *,
    user=None,
    host=None,
    dbname=None,
    port=None,
    data_dir=None,
    row_group_size=1024 * 1024,
    batched=True,
    threads=None,
    engine=None,
    numeric_mode=None,
    archive=False,
    archive_dir=None,
)

Export all tables in a PostgreSQL schema to Parquet files.

Parameters

Name	Type	Description	Default
schema	str	Name of the PostgreSQL database schema.	required
user	str	PostgreSQL user role. If not provided, defaults to the value of the PGUSER environment variable, or (if unset) the current system user.	None
host	str	Host name for the PostgreSQL server. If not provided, defaults to the value of the PGHOST environment variable, or "localhost" if unset.	None
dbname	str	Name of the PostgreSQL database. If not provided, defaults to the value of the PGDATABASE environment variable, or (if unset) the resolved user.	None
port	int	Port for the PostgreSQL server. If not provided, defaults to the value of the PGPORT environment variable, or 5432 if unset.	None
data_dir	str	Root directory of the Parquet data repository. If not provided, defaults to the value of the DATA_DIR environment variable, or the current working directory.	None
row_group_size	int	Maximum number of rows in each written Parquet row group. Must be positive. Default is 1024 * 1024.	1024 * 1024
batched	bool	Whether data are extracted in batches using to_pyarrow_batches() instead of a single call to to_pyarrow(). Using batches reduces memory usage for large tables at the cost of slightly lower performance.	True
threads	int	Number of threads DuckDB is allowed to use. If provided, must be positive.	None
engine	(duckdb, adbc)	Query execution engine used to read PostgreSQL data before writing Parquet.	"duckdb"
numeric_mode	(text, float64, decimal)	Handling for PostgreSQL NUMERIC columns. None keeps the engine-specific default: native decimals on DuckDB, text-backed numerics on ADBC.	"text"
archive	bool	Whether an existing Parquet file should be archived before being replaced.	False
archive_dir	str	Name of the directory (relative to data_dir/schema) where archived Parquet files will be stored.	None

Returns

Name	Type	Description
results	list[str]	List of Parquet file paths returned by db_to_pq(), one for each table in the schema.

Examples

>>> db_schema_to_pq("crsp")
>>> db_schema_to_pq("audit", archive=True)