README.md

pgx-fdw

Experimental Foreign Data Wrapper support for pgx.

Implementing a FDW

1. Impl the trait pgx_fdw::ForeignData

struct MyFdw {}
impl pgx_fdw::ForeignData for MyFdw {
    ...
}

2. Create handler function

/// ```sql
/// CREATE FUNCTION my_handler() RETURNS fdw_handler LANGUAGE c AS 'MODULE_PATHNAME', 'my_handler_wrapper';
/// ```
#[pg_extern]
fn my_handler() -> pg_sys::Datum {
    pgx_fdw::FdwState::<MyFdw>::into_datum()
}

3. Create wrapper + server

CREATE FOREIGN DATA WRAPPER my_handler handler my_handler NO VALIDATOR;
CREATE SERVER my_fdw_srv FOREIGN DATA WRAPPER my_handler OPTIONS (server_option '1', server_option '2');
CREATE FOREIGN TABLE users (
    id text,
    name text,
    email text
) SERVER my_fdw_server OPTIONS (
    table_option '1',
    table_option2 '2'
);

Examples

• inmem_table - Simple in-memory table fdw using Vec