Trigger wont release locks - oracle

Question

I am working on a project that will be replacing an existing older project. On one side I am taking data from external views and on the other I am taking the existing production data. The data between the two systems was supposed to have been in-sync, but they werent at any meaningful level. For the most part this has not been a huge issue as I have largely merged them where possible. In some cases the rows were matched on employee id's, and in others using only surname and birthdate.
The external view data always has two pieces of distinct information, an employee ID and another identifier. The Production data will always have one distinct ID and thats file_number. Sometimes production will have the external view keys, but this is not normal. These keys are the primary keys on either side, not surname and birthdate.
Its this last comparison which has caused the issue as we have several requirements where we are only allowed to join on this criteria, such as when the employee exists in the production side gets an entry on the external views. As surname and birthdate are not particularly distinct, I created an exclusion table for these records that would otherwise cause issues but are valid (twins for example). The exclusion table takes all of the offending records from both sides.
As I was unable to figure out a way to get some kind of constraint where these duplicate records would automatically get entered into the exclusion table (have poor control over data entry), I turned to triggers.
Error
Error report -
SQL Error: ORA-04021: timeout occurred while waiting to lock object
ORA-06512: at "USER.EXCLUSION_TRG", line 4
ORA-04088: error during execution of trigger 'USER.EXCLUSION_TRG'
ORA-06512: at "USER.VIEW_DUPLICATE_TRG", line 4
ORA-04088: error during execution of trigger 'USER.VIEW_DUPLICATE_TRG'
04021. 00000 - "timeout occurred while waiting to lock object %s%s%s%s%s"
*Cause: While waiting to lock a library object, a timeout is occurred.
*Action: Retry the operation later.
First trigger for VIEW Table
CREATE OR REPLACE TRIGGER VIEW_DUPLICATE_TRG
AFTER INSERT OR UPDATE ON VIEW_PERSON
BEGIN
INSERT INTO VIEW_EXCLUSION_PERSON (EMPLID, PRI, COMMENTS)
select emplid, PRI, 'VIEW CREATED '||SYSDATE from (
select upper(CONVERT(last_name, 'US7ASCII')) LAST_NAME, birthdate,first_name,emplid, pri, count(*) over (partition by upper(CONVERT(last_name, 'US7ASCII')), birthdate) duplicate_count from VIEW_PERSON
) K where duplicate_count > 1
and NOT EXISTS (select emplid from exclusion_person Z WHERE K.EMPLID=Z.EMPLID);
END;
Second trigger for Prod table
CREATE OR REPLACE TRIGGER PROD_DUPLICATE_TRG
AFTER INSERT OR UPDATE ON BACKGROUND_INFO
BEGIN
INSERT INTO EXCLUSION_PERSON (FILE_NUMBER, COMMENTS)
SELECT FILE_NUMBER, 'PROD CREATED '||SYSDATE
FROM BACKGROUND_INFO
WHERE (SURNAME, BIRTHDATE) IN
(SELECT SURNAME, BIRTHDATE
FROM BACKGROUND_INFO
GROUP BY SURNAME, BIRTHDATE
HAVING COUNT(*) > 1
)
AND FILE_NUMBER NOT IN (SELECT FILE_NUMBER FROM exclusion_person WHERE FILE_NUMBER IS NOT NULL);
END;
Third trigger for Exclusion table
CREATE OR REPLACE TRIGGER EXCLUSION_TRG
AFTER INSERT ON EXCLUSION_PERSON
DECLARE
PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
EXECUTE IMMEDIATE 'ALTER TRIGGER EXCLUSION_TRG DISABLE';
merge into EXCLUSION_PERSON E
using (select file_number, DECODE(TRIM(PRI), '99999999', NULL, PRI) PRI from administrative_info) A
on (E.PRI=A.PRI)
when matched then update set E.file_number = A.file_number, E.COMMENTS = E.COMMENTS||', MATCHED ON PRI ON '||SYSDATE
WHERE E.FILE_NUMBER IS NULL AND E.PRI IS NOT NULL AND A.PRI IS NOT NULL;
MERGE INTO VIEW_EXCLUSION_PERSON E
USING (SELECT FILE_NUMBER, EMPLID FROM VIEW_PERSON) P
ON (P.EMPLID = E.EMPLID)
WHEN MATCHED THEN UPDATE SET
E.FILE_NUMBER = P.FILE_NUMBER,
E.COMMENTS = E.COMMENTS||' MATCHED FROM PERSON '||SYSDATE
WHERE E.FILE_NUMBER IS NULL AND E.EMPLID IS NOT NULL AND P.FILE_NUMBER IS NOT NULL;
EXECUTE IMMEDIATE 'ALTER TRIGGER VIEW_DUPLICATE_TRG DISABLE';
MERGE INTO VIEW_PERSON P
USING (SELECT FILE_NUMBER, EMPLID FROM EXCLUSION_PERSON ) E
ON (P.EMPLID = E.EMPLID)
WHEN MATCHED THEN UPDATE SET P.FILE_NUMBER = E.FILE_NUMBER
WHERE P.FILE_NUMBER IS NULL AND E.EMPLID IS NOT NULL AND E.FILE_NUMBER IS NOT NULL;
EXECUTE IMMEDIATE 'ALTER TRIGGER VIEW_DUPLICATE_TRG ENABLE';
EXECUTE IMMEDIATE 'ALTER TRIGGER EXCLUSION_TRG ENABLE';
END;
So the issue seems to be that the first trigger VIEW_DUPLICATER_TRG is locking something and not releasing that lock when EXCLUSION_TRG is attempting to run. When I go looking for this %S%S%S%S%S object, I just cant find it, and none of my code is calling this object.

Answer 1

The major issue is here:
EXECUTE IMMEDIATE 'ALTER TRIGGER EXCLUSION_TRG DISABLE';
This tries to disable the trigger while the trigger itself is executing!
This will never work: you can't disable a trigger while it's executing. So to try to change its state from within its own execution will be blocked.
You can see this with the following:
create table t (
c1 int
);
create or replace trigger trg
after insert on t
declare
pragma autonomous_transaction;
begin
execute immediate 'alter trigger trg disable';
end;
/
insert into t values ( 1 );
The insert will be stuck, waiting to try and disable the trigger. But the trigger is executing. So you can't disable it. AAAAARGGGH!
This whole process needs redesigning. Ideally without any triggers!