一种简单的方法是创建存储过程，而不是触发器，例如add_foo（[parameters]），它将确定哪个分区适合向其中插入行并返回id（或新记录值，包括id）。例如：

A simpler way is to create stored procedure instead of the triggers, for example add_foo( [parameters] ), which would decide which partition is suitable to insert a row to and return id (or the new record values, including id). For example:

CREATE OR REPLACE FUNCTION add_foo(
    _d_id   INTEGER
,   _label  VARCHAR(4)
) RETURNS BIGINT AS $$
DECLARE
    _rec    foo%ROWTYPE;
BEGIN
    _rec.id := nextval('foo_id_seq');
    _rec.d_id := _d_id;
    _rec.label := _label;
    EXECUTE 'INSERT INTO foo_' || ( _d_id % 2 ) || ' SELECT $1.*' USING _rec;
    RETURN _rec.id;
END $$ LANGUAGE plpgsql;