CREATE OR REPLACE PACKAGE PKG_CLIENTS
...
 TYPE t_crm_cl IS TABLE OF CRM_CLIENTS@dblink%ROWTYPE;
 T_CRM_CLIENTS_REC t_crm_cl;
END;

CREATE OR REPLACE PACKAGE BODY PKG_CLIENTS
AS

...

        SELECT *
        BULK COLLECT
        INTO T_CF_CRM_CLIENTS_REC
        FROM CF_CRM_CLIENTS@dblink cf;

        MERGE INTO CLIENTS dst
        USING
        (
            SELECT
                cf.CRM_ID,
                ...
                pc.ID AS CLIENT_ID
            FROM
                --CRM_CLIENTS@dblink cf
                TABLE(T_CRM_CLIENTS_REC) cf
                INNER JOIN M_CLIENTS pc on pc.CRM_ID = cf.CRM_ID