Transaction inside a plpgsql function [duplicate]

问题

I have written a function for automation, mentioned below, which calls some other functions based on some rules. The function is giving me the desired results, but the problem that I am facing is that it does not commit the data after each of the function is processed internally. Once the main function gets completed only then it commits the entire data. I want to do a internal transaction which should commit the data as and when the internal function execution get completed. I tried giving a COMMIT statement after each of the PERFORM statements, but I got an error saying 'cannot begin/end transactions in PL/pgSQL'.

Can anyone suggest how do I go about doing a transaction inside a function.

CREATE OR REPLACE FUNCTION ccdb.fn_automation_for_updation()
  RETURNS void AS
$BODY$

DECLARE 
sec_col refcursor;
cnt integer;
sec_code ccdb.update_qtable%ROWTYPE;
new_cnt integer;

BEGIN

SELECT COUNT(*)
INTO cnt
FROM ccdb.update_qtable
WHERE status_flag IN (-1,1);

OPEN sec_col FOR
    SELECT * FROM ccdb.update_qtable WHERE status_flag IN (-1,1);

FOR i IN 1..cnt
LOOP

    FETCH sec_col INTO sec_code;

        PERFORM ccdb.o_dtr_update(sec_code.section_code);

        PERFORM ccdb.o_consumer_update_for_update(sec_code.section_code);

        PERFORM ccdb.o_consumer_update_for_insert(sec_code.section_code);

        PERFORM ccdb.o_bills_update_for_update(sec_code.section_code);

        PERFORM ccdb.o_bills_update_for_insert(sec_code.section_code);

        PERFORM ccdb.o_payments_update_for_update_new(sec_code.section_code);

        PERFORM ccdb.o_payments_update_for_insert(sec_code.section_code);

        PERFORM ccdb.o_payments_map_update_for_update(sec_code.section_code);

        PERFORM ccdb.o_payments_map_update_for_insert(sec_code.section_code);

        SELECT COUNT(*) INTO new_cnt FROM ccdb.update_qtable WHERE status_flag IN (-1,1);

        IF new_cnt > cnt
        THEN
            CLOSE sec_col;

            OPEN sec_col FOR
                SELECT * FROM ccdb.update_table WHERE status_flag IN (-1,1);

        cnt := new_cnt;

        END IF;

END LOOP;

CLOSE sec_col;

END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;