ORA-30926: unable to get a stable set of rows in the source tables - sql

Question

I have a customer who gets: ORA-30926: unable to get a stable set of rows in the source tables:
Log show error Massage Error (30926)
13:52:19 (00:00:02.406) ERROR : Error (30926) (00:00:02.406) ORA-30926: Stabile Zeilengruppe in den Quelltabellen kann nicht eingelesen werden
TS03_MIN0100: UpdTable failed. Update inv_value in cMinTimeTable:
MERGE INTO HUBWBPMS5_ENTTS03005400223 a USING ( SELECT DISTINCT a.inv_value +
( a.inv_value_sum - h.inv_value ) AS inv_value , a.rowid xzfd_rid
FROM HUBWBPMS5_ENTTS03005700223 h , HUBWBPMS5_ENTTS03005400223 a
WHERE a.voucher_no = h.voucher_no AND a.sequence_no = h.max_seq_no
AND a.client = h.client ) xzfd_t ON ( xzfd_t.xzfd_rid = a.rowid )
WHEN MATCHED THEN
UPDATE
SET a.inv_value = xzfd_t.inv_value
I have checked for duplicate values in the tables but cant find anything unusual.
Maybe someone has an idea that could be useful.
The query is:
Query causing error (temp table):
INSERT INTO HUBWBPMS5_ENTTS03005700228 ( agg_flag , ace_code , activity , category , client , cost_dep , description , dim1 , dim2 , dim3 , dim4 , inc_ref , inv_value , max_seq_no , pd , period , project , resource_id , resource_typ , trans_date , unit , voucher_no , work_order , work_type )
SELECT agg_flag , ace_code , activity , category , client , cost_dep , description , dim1 , dim2 , dim3 , dim4 , inc_ref , SUM ( inv_value ) inv_value , max_seq_no , pd , period , project , resource_id , resource_typ , trans_date , unit , voucher_no , work_order , work_type
FROM HUBWBPMS5_ENTTS03005400228
WHERE agg_flag = 1
GROUP BY agg_flag , ace_code , activity , category , client , cost_dep , description , dim1 , dim2 , dim3 , dim4 , period , trans_date , voucher_no , max_seq_no , inc_ref , pd , project , resource_id , resource_typ , unit , work_order , work_type

Answer 1

When you get that error, it will be from a MERGE statement, and it indicates that there are multiple rows in the source dataset that match to a row you're joining to in the target table, and as such, Oracle doesn't know which one to use to do the update.
Taking your merge statement:
MERGE INTO HUBWBPMS5_ENTTS03005400223 a
USING (SELECT DISTINCT a.inv_value + ( a.inv_value_sum - h.inv_value ) AS inv_value,
a.rowid xzfd_rid
FROM HUBWBPMS5_ENTTS03005700223 h,
HUBWBPMS5_ENTTS03005400223 a
WHERE a.voucher_no = h.voucher_no
AND a.sequence_no = h.max_seq_no
AND a.client = h.client) xzfd_t
ON (xzfd_t.xzfd_rid = a.rowid)
WHEN MATCHED THEN
UPDATE SET a.inv_value = xzfd_t.inv_value;
it looks like the join between the two tables HUBWBPMS5_ENTTS03005700223 and HUBWBPMS5_ENTTS03005400223 in the xzfd_t subquery causes multiple rows to be returned for one or more of the HUBWBPMS5_ENTTS03005400223 rows (ie. you get multiple rows returned for at least one a.rowid).
To check this, run:
SELECT xzfd_rid,
COUNT(*) cnt
FROM (SELECT DISTINCT a.inv_value + ( a.inv_value_sum - h.inv_value ) AS inv_value,
a.rowid xzfd_rid
FROM HUBWBPMS5_ENTTS03005700223 h,
HUBWBPMS5_ENTTS03005400223 a
WHERE a.voucher_no = h.voucher_no
AND a.sequence_no = h.max_seq_no
AND a.client = h.client)
GROUP BY xzfd_rid
HAVING COUNT(*) > 1;
In order to fix this, you'd need to make the xzfd_t subquery return a single row for each xzfd_rid. Possibly using row_number() to pick a single row, or an aggregate query to sum up all the h.inv_value fields per a.rowid instead of the DISTINCT.