I recently encountered a Strange issue on Merge statement. It failed with ORA 30926 error.
I have already checked for the below pitfalls,
Duplicate records check in Source and Target table – Came out clean
Source and Target tables Analyze structure – Came out clean
Source and Target tables Indexes Analyze structure – Came out clean
Same Merge SQL when DBA tried in SYS user – Worked. Still Puzzling
Same Merge SQL runs successfully in Copy table of Target – Worked. Still Puzzling
DBA Bounced the TEST server. Though not convincing wanted to give a try as the issue appears to be strange – Didn’t Workout
Gathered the statistics
Truncate the Original target table and reload from Copy table and try the Merge again - Didn't Workout. Failed with same error
Nutshell Script:
MERGE INTO TGT_SCHEMA.EMP T
USING SRC_SCHEMA.S_EMP S
ON
(
T.EMPLOYEE_NO = S.EMPLOYEE_NO AND
T.START_DATE = S.START_DATE
)
Unique Index (EMPLOYEE_NO, START_DATE) exists on Target table and a normal Index of same combination exists on Source table. Target table is a partitioned table and there are some VPD policies applied to other columns.
My Database version : Oracle 11.2.0.3.0
If you really checked everything you said correctly, then this is a bit of a puzzler. I think #4 in your diagnostic checklist may be telling: that the same statement worked when executed as SYS.
For fun, check to see where there are any VPD policies on either table (DBMS_RLS package). If there are, try to disable them and retry the merge.
This error happens on MERGE when the USING clause returns more than one row for one or more target rows according to your matching criteria. Since it can't know which of two updates to do first, it gives up.
Run:
SELECT matching_column1, ..matching_ColumnN, count(*)
FROM (
<your USING query>
)
group by matching_column1, ..matching_ColumnN
having count(*) > 1
To find the offending source data. At that point either modify your USING query to resolve it, change your matching criteria, or clean up bad data - whichever is appropriate.
EDIT - Add another item:
One other possibility - you will get this error if you try to update a column in your target that is referenced in your ON clause.
So make sure that you are not trying to UPDATE the EMPLOYEE_NO or START_DATE fields.
Related
I've gotten to one of those places where I've been toying with something for a little while trying to figure out why its not working and figured I would ask here. I am currently in the middle of making adjustments to a batch process that involves creating an external table A used for staging and then transferring the data from that table over to Table B for further processing.
There's a step in the batch that was there before to load all that data and it goes like this:
INSERT INTO TABLE B SELECT * FROM TABLE A
Upon running this statement in batch and outside of it in Oracle Developer I get the following error:
Run query ORA-00932: inconsistent datatypes: expected DATE got NUMBER
I went through my adjustments line by line and made sure I had the right data types. I also went over the data itself the best I could and from what I can tell it seems normal also. In an effort to find which individual field could have been having the error, I attempted to load data from Table A to Table B one column at a time...Doing this I received no errors which shocked me somewhat. If I use the SQL below and have all the fields listed out individually, the load of all the data works flawlessly. Can someone explain why this might be? Does the below function perform an internal Oracle working that the previous one does not?
insert into TABLE B (
COLUMN_ONE,
COLUMN_TWO,
COLUMN_THREE
.
.
.)
select
COLUMN_ONE,
COLUMN_TWO,
COLUMN_THREE
.
.
.
from TABLE A;
Well, if you posted description of tables A and B, we could see it ourselves. As it is now, we have to trust what you're saying, i.e. that everything matches (but Oracle disagrees), so I don't know what to say.
On the other hand, I've learnt that using
INSERT INTO TABLE B SELECT * FROM TABLE A
is a poor way of handling things (unless that's a quick & dirty testing). I try to always name all columns I'm working with, no matter how many of them are involved in that very operation. As you noticed, that seems to be working well for you too, so I'd suggest you to keep doing it.
I am using sequences to create IDs, so while executing insert stored procedure it will create unique value for ID. But after some time it is losing the definition for the sequence.
Not sure why this is happening again and again and how to solve the problem?
I am using Oracle SQL Developer and in the edit table property there is 'Identity Column' setting. See below:
Next step is setting up trigger and sequence:
It was working fine for some time until this property defaulted. Now it is not there anymore:
Still have this trigger and sequence object in the schema and able to setup again but it will break later.
How to avoid this problem in future?
I think it is just a bug/limitation in your client software, Oracle SQL Developer. The "Identity Column" tab is a handy way to create the corresponding sequence and trigger but it doesn't seem to recognise existing elements. I've just verified my own system and that's exactly what happens.
It makes sense, because adding a new sequence and trigger is a pretty straightforward task (all you need is a template) but displaying current sequence is hard given that a trigger can implement any conceivable logic. Surely it could be done but the cost-benefit ratio probably left things this way.
In short, your app is not broken so nothing needs to be fixed on your side.
This is what I received from IT support regarding the issue:
A few possibilities that might cause this:
1 - Another user with limited privileges might be editing the table using SQL Developer. In this case, if this user's privilege is not enough to obtain the sequence and/or trigger information from the database, the tool might leave the fields blank and disable it when table changes are saved.
2 - The objects are being changed or removed outside of SQL Developer, causing it to lose the information. In my tests I noticed that dropping the trigger and recreating it with the same name caused the identity property information to be lost on SQL Developer.
Even being the trigger enabled, and working for inserts it could not retrieve the information.
Then, if I run an alter trigger to enable it (even tough dba_trigger is reporting it as already enabled), SQL Developer will list the information again:
ALTER TRIGGER "AWS"."TABLE1_TRG" ENABLE;
So it looks like there are some issues with the SQL Developer, that is causing this behavior.
Next time it happen, please check if the trigger still exist on the database and is enabled with the query below:
select owner, trigger_name, TRIGGER_TYPE, TRIGGERING_EVENT, TABLE_OWNER, TABLE_NAME, STATUS
from dba_triggers
where trigger_name = 'ENTER_YOUR_TRG_NAME'; --Just change the trigger name in WHERE
I'm using a Win XP box with BDE Administrator and Access 2007 installed. I'm able to open and perform select queries on existing Paradox tables without problem but have some very strange behavior when attempting INSERT/UPDATE. I can even create a new Paradox table and it has the same behavior. Here is sample code:
' create new table
conObj.Execute "CREATE TABLE test (id INT, comment VARCHAR(30))"
' first insert works fine
conObj.Execute "INSERT INTO test VALUES (1, 'something')"
' second insert fails for unknown reason
conObj.Execute "INSERT INTO test VALUES (2, 'something else')"
I've tried using Jet 4.0, MS Access Paradox driver, and native Paradox driver connection strings but all yield the same result. On the second insert statement it throws an error:
Operation must be an updateable query
I've read numerous posts in forums and pages on help sites that tell me this error is caused by a file permissions issue. The account running this script is part of the Administrator group and I've changed file permissions to allow the Everyone group Full Control of the db file but this changes nothing.
This page put out by Micrsoft Support did not fix the problem: http://support.microsoft.com/kb/175168
Additionally, I can create a new table but any time I try to create a PRIMARY KEY or UNIQUE field I get an error message that says:
"Index_[random characters] is not a valid name."
try
"CREATE TABLE test (id INT, comment VARCHAR(30), primary key(id))"
I don't know much about Paradox databases but this has indeed been a learning experience. Even though I have a table file called table.db that's not enough to store more than a single row of data. I also need several other files to insert or update a paradox database:
table.DB
table.PX
table.VAL
table.XG0
table.XG1
table.YG0
table.YG1
I was nosing around in another program that generates paradox databases and found when I copied a blank database from it along with these other files it generated I was able to insert and update without problems. I have no idea what these files are for or why they need to be present to insert or update but having them present fixed my issue.
I apologize for posting a question that seems to have been asked numerous times on the internet, but I can't quite fix it for some reason.
I was trying to populate some tables using Oracle's magical sqldr utility, but it throws an ORA-01775 error for some reason.
Everywhere I go on Google, people say something along the lines of: "Amateur, get your synonyms sorted out" (that was paraphrased) and that's nice and all, but I did not make any synonyms.
Here, the following does not work on my system:
SQLPLUS user/password
SQL>CREATE TABLE test (name varchar(10), id number);
SQL>exit
Then, I have a .ctl file with the following contents:
load data
characterset utf16
infile *
append
into table test
(name,
id
)
begindata
"GURRR" 4567
Then I run this command:
sqlldr user#localhost/password control=/tmp/controlfiles/test.ctl
The result:
SQL*Loader-702: Internal error - ulndotvcol: OCIStmtExecute()
ORA-01775: looping chain of synonyms
Part of test.log:
Table TEST, loaded from every logical record.
Insert option in effect for this table: APPEND
Column Name Position Len Term Encl Datatype
------------------------------ ---------- ----- ---- ---- ---------------------
NAME FIRST 2 CHARACTER
ID NEXT 2 CHARACTER
SQL*Loader-702: Internal error - ulndotvcol: OCIStmtExecute()
ORA-01775: looping chain of synonyms
And, if I try to do a manual insert:
SQL> insert into test values ('aa', 56);
1 row created.
There is no problem.
So, yeah, I am stuck!
If it helps, I am using Oracle 11g XE on CentOS.
Thanks for the help guys, I appreciate it.
EDIT:
I kind of, sort of figured out part of the problem. The problem was that somewhere along the line, maybe during a failed load or something, Oracle had given itself corrupt views and synonyms.
The affected views were: GV_$LOADISTAT, GV_$LOADPSTAT, V_$LOADISTAT and V_$LOADPSTAT. I am not quite sure why the views got corrupt, but recompiling them resulted in compiled with errorserrors. The synonyms used in the queries themselves were corrupt, namely the gv$loadistat, gv$loadpstat, v$loadistat and v$loadpstat synonyms.
I wasn't sure about why this was happening and I didn't quite understand anything. So, I decided to drop the synonyms and recreate them. Unfortunately, I couldn't recreate them, as the view they pointed to (there is a bit of weird recursion going on here...) was corrupt. These views were the aforementioned GV_$LOADISTAT and other views. In other words, the synonyms pointed to the views that used those synonyms. Talk about a looping chain.
So...I recreated the public synonyms but instead of specifying the view as GV_$LOADISTAT, I specified them as sys.GV_$LOADISTAT. e.g.
DROP PUBLIC synonym GV$LOADISTAT;
CREATE PUBLIC synonym GV$LOADISTAT for sys.GV_$LOADISTAT;
Then, I recreated the user views to point to those public synonyms.
CREATE OR REPLACE FORCE VIEW "USER"."GV_$LOADISTAT" ("INST_ID", "OWNER", "TABNAME", "INDEXNAME", "SUBNAME", "MESSAGE_NUM", "MESSAGE")
AS
SELECT "INST_ID",
"OWNER",
"TABNAME",
"INDEXNAME",
"SUBNAME",
"MESSAGE_NUM",
"MESSAGE"
FROM gv$loadistat;
That seemed to fix the views/synonyms. Yeah, it is a bit of a hack, but it somehow worked. Unfortunately, this was not enough to run SQL Loader. I got a table or view does not exist error.
I tried granting more permissions to my regular user, but it didn't work. So, I gave up and ran SQL Loader as sysdba. It worked! It is not a good thing to do, but it is a development only system made for testing purposes, so, I didn't care.
I could not repeat your looping synonym chain error, but it appears the control file needed a bit of work, at least for my environment.
I was able to get your example to work by modifying it thusly:
load data
infile *
append
into table test
fields terminated by "," optionally enclosed by '"'
(name,
id
)
begindata
"GURRR",4567
I am getting
ORA-30926: unable to get a stable set of rows in the source tables
in the following query:
MERGE INTO table_1 a
USING
(SELECT a.ROWID row_id, 'Y'
FROM table_1 a ,table_2 b ,table_3 c
WHERE a.mbr = c.mbr
AND b.head = c.head
AND b.type_of_action <> '6') src
ON ( a.ROWID = src.row_id )
WHEN MATCHED THEN UPDATE SET in_correct = 'Y';
I've ran table_1 it has data and also I've ran the inside query (src) which also has data.
Why would this error come and how can it be resolved?
This is usually caused by duplicates in the query specified in USING clause. This probably means that TABLE_A is a parent table and the same ROWID is returned several times.
You could quickly solve the problem by using a DISTINCT in your query (in fact, if 'Y' is a constant value you don't even need to put it in the query).
Assuming your query is correct (don't know your tables) you could do something like this:
MERGE INTO table_1 a
USING
(SELECT distinct ta.ROWID row_id
FROM table_1 a ,table_2 b ,table_3 c
WHERE a.mbr = c.mbr
AND b.head = c.head
AND b.type_of_action <> '6') src
ON ( a.ROWID = src.row_id )
WHEN MATCHED THEN UPDATE SET in_correct = 'Y';
You're probably trying to to update the same row of the target table multiple times. I just encountered the very same problem in a merge statement I developed. Make sure your update does not touch the same record more than once in the execution of the merge.
A further clarification to the use of DISTINCT to resolve error ORA-30926 in the general case:
You need to ensure that the set of data specified by the USING() clause has no duplicate values of the join columns, i.e. the columns in the ON() clause.
In OP's example where the USING clause only selects a key, it was sufficient to add DISTINCT to the USING clause. However, in the general case the USING clause may select a combination of key columns to match on and attribute columns to be used in the UPDATE ... SET clause. Therefore in the general case, adding DISTINCT to the USING clause will still allow different update rows for the same keys, in which case you will still get the ORA-30926 error.
This is an elaboration of DCookie's answer and point 3.1 in Tagar's answer, which from my experience may not be immediately obvious.
How to Troubleshoot ORA-30926 Errors? (Doc ID 471956.1)
1) Identify the failing statement
alter session set events ‘30926 trace name errorstack level 3’;
or
alter system set events ‘30926 trace name errorstack off’;
and watch for .trc files in UDUMP when it occurs.
2) Having found the SQL statement, check if it is correct (perhaps using explain plan or tkprof to check the query execution plan) and analyze or compute statistics on the tables concerned if this has not recently been done. Rebuilding (or dropping/recreating) indexes may help too.
3.1) Is the SQL statement a MERGE?
evaluate the data returned by the USING clause to ensure that there are no duplicate values in the join. Modify the merge statement to include a deterministic where clause
3.2) Is this an UPDATE statement via a view?
If so, try populating the view result into a table and try updating the table directly.
3.3) Is there a trigger on the table? Try disabling it to see if it still fails.
3.4) Does the statement contain a non-mergeable view in an 'IN-Subquery'? This can result in duplicate rows being returned if the query has a "FOR UPDATE" clause. See Bug 2681037
3.5) Does the table have unused columns? Dropping these may prevent the error.
4) If modifying the SQL does not cure the error, the issue may be with the table, especially if there are chained rows.
4.1) Run the ‘ANALYZE TABLE VALIDATE STRUCTURE CASCADE’ statement on all tables used in the SQL to see if there are any corruptions in the table or its indexes.
4.2) Check for, and eliminate, any CHAINED or migrated ROWS on the table. There are ways to minimize this, such as the correct setting of PCTFREE.
Use Note 122020.1 - Row Chaining and Migration
4.3) If the table is additionally Index Organized, see:
Note 102932.1 - Monitoring Chained Rows on IOTs
Had the error today on a 12c and none of the existing answers fit (no duplicates, no non-deterministic expressions in the WHERE clause). My case was related to that other possible cause of the error, according to Oracle's message text (emphasis below):
ORA-30926: unable to get a stable set of rows in the source tables
Cause: A stable set of rows could not be got because of large dml activity or a non-deterministic where clause.
The merge was part of a larger batch, and was executed on a live database with many concurrent users. There was no need to change the statement. I just committed the transaction before the merge, then ran the merge separately, and committed again. So the solution was found in the suggested action of the message:
Action: Remove any non-deterministic where clauses and reissue the dml.
SQL Error: ORA-30926: unable to get a stable set of rows in the source tables
30926. 00000 - "unable to get a stable set of rows in the source tables"
*Cause: A stable set of rows could not be got because of large dml
activity or a non-deterministic where clause.
*Action: Remove any non-deterministic where clauses and reissue the dml.
This Error occurred for me because of duplicate records(16K)
I tried with unique it worked .
but again when I tried merge without unique same proble occurred
Second time it was due to commit
after merge if commit is not done same Error will be shown.
Without unique, Query will work if commit is given after each merge operation.
I was not able to resolve this after several hours. Eventually I just did a select with the two tables joined, created an extract and created individual SQL update statements for the 500 rows in the table. Ugly but beats spending hours trying to get a query to work.
As someone explained earlier, probably your MERGE statement tries to update the same row more than once and that does not work (could cause ambiguity).
Here is one simple example. MERGE that tries to mark some products as found when matching the given search patterns:
CREATE TABLE patterns(search_pattern VARCHAR2(20));
INSERT INTO patterns(search_pattern) VALUES('Basic%');
INSERT INTO patterns(search_pattern) VALUES('%thing');
CREATE TABLE products (id NUMBER,name VARCHAR2(20),found NUMBER);
INSERT INTO products(id,name,found) VALUES(1,'Basic instinct',0);
INSERT INTO products(id,name,found) VALUES(2,'Basic thing',0);
INSERT INTO products(id,name,found) VALUES(3,'Super thing',0);
INSERT INTO products(id,name,found) VALUES(4,'Hyper instinct',0);
MERGE INTO products p USING
(
SELECT search_pattern FROM patterns
) o
ON (p.name LIKE o.search_pattern)
WHEN MATCHED THEN UPDATE SET p.found=1;
SELECT * FROM products;
If patterns table contains Basic% and Super% patterns then MERGE works and first three products will be updated (found). But if patterns table contains Basic% and %thing search patterns, then MERGE does NOT work because it will try to update second product twice and this causes the problem. MERGE does not work if some records should be updated more than once. Probably you ask why not update twice!?
Here first update 1 and second update 1 are the same value but only by accident. Now look at this scenario:
CREATE TABLE patterns(code CHAR(1),search_pattern VARCHAR2(20));
INSERT INTO patterns(code,search_pattern) VALUES('B','Basic%');
INSERT INTO patterns(code,search_pattern) VALUES('T','%thing');
CREATE TABLE products (id NUMBER,name VARCHAR2(20),found CHAR(1));
INSERT INTO products(id,name,found) VALUES(1,'Basic instinct',NULL);
INSERT INTO products(id,name,found) VALUES(2,'Basic thing',NULL);
INSERT INTO products(id,name,found) VALUES(3,'Super thing',NULL);
INSERT INTO products(id,name,found) VALUES(4,'Hyper instinct',NULL);
MERGE INTO products p USING
(
SELECT code,search_pattern FROM patterns
) s
ON (p.name LIKE s.search_pattern)
WHEN MATCHED THEN UPDATE SET p.found=s.code;
SELECT * FROM products;
Now first product name matches Basic% pattern and it will be updated with code B but second product matched both patterns and cannot be updated with both codes B and T in the same time (ambiguity)!
That's why DB engine complaints. Don't blame it! It knows what it is doing! ;-)