multicorn

pig repo add pgdg -u    # add pgdg repo and update cache

pig install multicorn;		# install via package name, for the active PG version

pig install multicorn -v 18;   # install for PG 18
pig install multicorn -v 17;   # install for PG 17
pig install multicorn -v 16;   # install for PG 16
pig install multicorn -v 15;   # install for PG 15
pig install multicorn -v 14;   # install for PG 14

CREATE EXTENSION multicorn;

from multicorn import ForeignDataWrapper

class MyFDW(ForeignDataWrapper):
    def __init__(self, options, columns):
        super().__init__(options, columns)
        self.options = options
        self.columns = columns

    def execute(self, quals, columns):
        """Yield rows as dictionaries. quals contains WHERE pushdown info."""
        yield {"id": 1, "name": "example"}

    def insert(self, new_values):
        """Handle INSERT operations."""
        pass

    def update(self, old_values, new_values):
        """Handle UPDATE operations."""
        pass

    def delete(self, old_values):
        """Handle DELETE operations."""
        pass

CREATE EXTENSION multicorn;

CREATE SERVER multicorn_srv FOREIGN DATA WRAPPER multicorn
  OPTIONS (wrapper 'myfdw.MyFDW');

CREATE FOREIGN TABLE my_table (
  id integer,
  name text
)
SERVER multicorn_srv
OPTIONS (
  option1 'value1'
);

SELECT * FROM my_table;

CREATE SERVER csv_srv FOREIGN DATA WRAPPER multicorn
  OPTIONS (wrapper 'multicorn.csvfdw.CsvFdw');

CREATE FOREIGN TABLE csvtest (
  col1 text,
  col2 text
)
SERVER csv_srv
OPTIONS (
  filename '/tmp/data.csv',
  skip_header '1',
  delimiter ','
);