ORA-01775: boucle de la chaîne de synonymes, mais il n'y a pas des synonymes

Ne peuvent pas comprendre pourquoi je me fais 'Instruction SQL ignoré" et "ORA-01775: boucle de la chaîne de synonymes", sur la ligne 52 de la présente procédure stockée. Vous avez des idées?

CREATE OR REPLACE PACKAGE PURGE_LOG_BY_EVENT_DAYS AS
TYPE dual_cursorType IS REF CURSOR RETURN dual%ROWTYPE;
PROCEDURE log_master_by_event_days (event_id NUMBER, purge_recs_older_than NUMBER, result_cursor OUT dual_cursorType);
END PURGE_LOG_BY_EVENT_DAYS;
/
CREATE OR REPLACE PACKAGE BODY PURGE_LOG_BY_EVENT_DAYS
AS
err_msg     VARCHAR2(4000);
PROCEDURE log_master_by_event_days (event_id NUMBER, purge_recs_older_than NUMBER, result_cursor OUT dual_cursorType)
IS
TYPE  type_rowid IS TABLE OF ROWID INDEX BY BINARY_INTEGER;
TYPE  type_ref_cur IS REF CURSOR;
l_rid                   type_rowid;
c1                      type_ref_cur;
l_sql_stmt              VARCHAR2(4000);
proc_start_time         DATE := sysdate;
purge_date              DATE;
l_bulk_collect_limit    NUMBER := 1000;
retry                   NUMBER := 5;
retry_count             NUMBER := 0; 
loop_count              NUMBER := 0;
err_code                VARCHAR2(10);
BEGIN
purge_date := to_date(sysdate - purge_recs_older_than);
l_sql_stmt := '';
l_sql_stmt := l_sql_stmt ||' SELECT rowid FROM LOG_MASTER ';
l_sql_stmt := l_sql_stmt ||'  WHERE last_changed_date < :purge_date';
l_sql_stmt := l_sql_stmt ||'    AND event_id = :event_id';
-- The following while loop
-- executes the purge code
-- 'retry' number of times in case of ORA-01555
WHILE retry > 0 LOOP
BEGIN
-- START of purge code
OPEN c1 FOR l_sql_stmt USING purge_date, event_id;
LOOP
FETCH c1 BULK COLLECT into l_rid LIMIT l_bulk_collect_limit;
FORALL i IN 1..l_rid.COUNT
DELETE from log_master
WHERE rowid = l_rid(i);
COMMIT;
loop_count := loop_count + 1;
EXIT WHEN c1%NOTFOUND;
END LOOP;
CLOSE c1;
-- End of purge code
-- if processing reached this point
-- Process completed successfuly, set retry = 0 to exit loop
retry := 0;
EXCEPTION
WHEN OTHERS THEN
-- ====================================
-- Get error msg
-- ====================================
ROLLBACK;
err_code := sqlcode;
dbms_output.put_line(err_code);
-- ====================================
-- Check if it is 01555
-- if so retry, else exit loop
-- ====================================
retry := retry - 1;
if err_code = '-1555' and retry > 0 THEN
CLOSE c1;
retry_count :=  retry_count + 1;
else
err_msg := sqlerrm;
exit;
end if;
END;
END LOOP;
IF err_msg IS NULL THEN
open result_cursor for select '1 - PURGE_LOG_BY_EVENT_DAYS ran successfully (event_id : '||event_id||', loop_count : '||loop_count||', bulk_limit : '||l_bulk_collect_limit||', retries : '||retry_count||') ' from dual;
ELSE
open result_cursor for select '2 - PURGE_LOG_BY_EVENT_DAYS After (event_id : '||event_id||', loop_count : '||loop_count||', bulk_limit : '||l_bulk_collect_limit||', retries : '||retry_count||') with Error: ' || err_msg from dual;
END IF;
END log_master_by_event_days;
END PURGE_LOG_BY_EVENT_DAYS;