I creat a procedure . when i am going to run my procedure the following error araise, please helpe me . it is very urgent.

SQL> EXECUTE PROC_INF_VERTICALS_Q
BEGIN PROC_INF_VERTICALS_Q; END;

*
ERROR at line 1:
ORA-30926: unable to get a stable set of rows in the source tables
ORA-02063: preceding line from STAGEDB_LINK
ORA-06512: at "CASEADMIN.PROC_INF_VERTICALS_Q", line 4
ORA-06512: at line 1



SQL> ED
Wrote file afiedt.buf

1 select * from all_tab_columns
2* where column_name ='QUA_DAT_CODE'
SQL> /

OWNER TABLE_NAME COLUMN_NAME DATA_TYPE
------------------------------ ------------------------------ ------------
CASEADMIN INF_HORIZONTALS_A QUA_DAT_CODE NUMBER
CASEADMIN INF_VERTICALS_Q QUA_DAT_CODE NUMBER





CREATE OR REPLACE PROCEDURE "CASEADMIN".PROC_INF_VERTICALS_Q IS
BEGIN

MERGE INTO "STAGEADMIN".INF_VERTICALS_Q@stagedb_link T
USING "CASEADMIN".INF_VERTICALS_Q S
ON (T.QUA_DAT_CODE = S.QUA_DAT_CODE)
WHEN MATCHED THEN
UPDATE SET


T.TEXT = S.TEXT,
T.SEQ = S.SEQ,
T.QUA_SEQ = S.QUA_SEQ

WHEN NOT MATCHED THEN
INSERT VALUES (
S.QUA_DAT_CODE,
S.TEXT,
S.SEQ,
S.QUA_SEQ);

Commit;
END;


Thanks