Change Data Capture: Unsubscribed column results in new change set record

I have an installation using Oracle 11g Change Data Capture in synchronous mode. As of writing, I have a single publication and a single subscription. The setup is pretty basic:
PUB_TABLE
PUB_ID*
PUB_NAME*
PUB_USELESS_FLAG
* columns are included in both the PUBLICATION and the SUBSCRIPTION. The final column is of no consequence and is excluded from both the PUBLICATION and SUBSCRIPTION.
My problem is that any time PUB_USELESS_FLAG gets updated (even if no other columns are changed), a record is written to not only the change table but the change table view. The table in question has a significant number of transactions logged against it, but only a subset of those changes are of note to the subscriber (which is why the subscriber does not listen to every column). However, since the subscription is receiving records for every change to the source table, the result is an enormous amount of overhead as the subscriber is forced to sift through numerous records that are of no consequence.
I read the Change Data Capture manual for Oracle 11g; I could not find any reference to the observed functionality. Is this a consequence of using synchronous vs. asynchronous modes of capture? Is there an option to only receive changes on subscribed columns?
Thanks in advance

Bring this to the top because I have the same question. This website (http://www.bikinfo.com/HTML/CDC/CDC_Article.html) makes it sound like this problem is unavoidable.
Edited by: nik_m on Nov 10, 2011 8:04 AM
Edited by: nik_m on Nov 10, 2011 8:05 AM

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Change Data Capture in SQL Server

Post Author: rtamanji
CA Forum: Data Integration
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It is not using triggers. The source is the transaction log.
Related link:
Basics of Change Data Capture
...The source of change data for change data capture is the SQL Server transaction log. As inserts, updates, and deletes are applied to tracked source tables, entries that describe those
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environment. ...
Kalman Toth, SQL Server & Business Intelligence Training; SQL Server 2008 Training

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Setting up CDC is a fairly complex process with different options. Setting just the filter in OWB is only a very small part.
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http://www.rittmanmead.com/2009/10/changed-data-capture-and-owb11gr2/
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http://www.rittmanmead.com/2006/04/asynchronous-hotlog-distributed-change-data-capture-and-owb-paris/
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Thanks in advance for your time and help!
Jarret

This is called a deffered update. It is the way that some tables are updated - ie a delete followed by an insert.
See if the behavior still occurs when using trace flag 8201, ie
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I am enabling Change data capture (CDC) on SQL server 2012 Enterprise edition(11.0.2100.60)
. I am able to enable it on Database level with below SQL, but failed to enable on Table level.
Use DatabaseName
GO
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GO
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@source_name = N'TableName', @role_name = NULL
GO
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Use the action and error to determine the cause of the failure and resubmit the request.'.
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http://social.technet.microsoft.com/Forums/sqlserver/en-US/fa0c2a52-63b5-4a39-9f35-fe6f0eb21d1d/change-data-capture-on-table?forum=sqldatawarehousing
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Hii,
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SQL>execute dbms_cdc_subscribe.create_subscription(-
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description => 'This subscription is used for testing',-
subscription_name => 'TEST_SUBSCRIPTION');
ERROR at line 1:
ORA-06550: line 1, column 26:
PLS-00302: component 'CREATE_SUBSCRIPTION' must be declared
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If this package is exists DBMS_CDC_SUBSCRIBE then that Version will support this feature thats my understand.
This is successfully worked on our DB. Please check syntax like which may have space or anything...
Replace with your parameters and run, use notepad.
BEGIN
DBMS_CDC_SUBSCRIBE.CREATE_SUBSCRIPTION(
change_set_name => 'PROD1DB_CHANGES',
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END;
/

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Hi,
I am new to BODI and currently trying to design a change data capture approach.
In other ETL tools i have used, the last session run timestamp is stored as a parameter and can be called within a mapping. So the mapping updates this parameter everytime it runs. Therefore when implementing CDC the load_date on the table has to be compared to this parameter.
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I appreciate your help.
Thanks
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Yes, there is such a concept, you have to build it yourself. e.g. https://wiki.sdn.sap.com:443/wiki/display/BOBJ/Inititialize-End+Script
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Change Data Capture,Change Tables

Hi,
We installed Change Data Capture in our DB (10gR2),however there is a problem with change tables.Change tables are being cleaned somehow.According to text quoted below,the job which is cleaning change tables is cdc$_default_purge_job.However
select log_date
+, job_name+
+, status+
from dba_scheduler_job_log
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results no data. Also this morning i came across that data cleansing again, and run the query below.And again no result.
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+, cpu_used+
from dba_scheduler_running_jobs;
/*We didn't even use DBMS_SCHEDULER.SET_ATTRIBUTE procedure so far*/
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Tnx in advance
Quotation:
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DBMS_CDC_PUBLISH.PURGE procedure to remove data that subscribers are no longer using from the change tables. This job has the name
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DBMS_SCHEDULER.SET_ATTRIBUTE and set the
repeat_interval attribute. You can verify or modify any other attributes with the
DBMS_SCHEDULER package.

Setting up CDC is a fairly complex process with different options. Setting just the filter in OWB is only a very small part.
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http://www.rittmanmead.com/2009/10/changed-data-capture-and-owb11gr2/
Plus and older one illustrating how to use Oracle logs;
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Cheers
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change_set_name     => 'DEMANTRA_SOURCE',
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column_type_list     => 'SDATE DATE ,LEVEL1 VARCHAR2(2000) ',
capture_values     => 'new',
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source_colmap     => 'n',
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I'm afraid this is not possible!!!!

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Hi,
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ORA-012024:Cannot select FOR UPDATE from view with DISTINCT,GROUP by etc..
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Distributed Hotlog Change Data Capture (CDC) on 10.2.0.3 - Very Urgent

Hello all,
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We tried runnning this:
begin
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          column_type_list => 'col1 number, col2 varchar2(20)',
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          user_id => 'n',
          timestamp => 'n',
          object_id => 'n',
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I sometimes get this:
begin
ERROR at line 1:
ORA-00942: table or view does not exist
ORA-06512: at "SYS.DBMS_CDC_PUBLISH", line 611
ORA-06512: at line 2
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begin
ERROR at line 1:
ORA-31532: cannot enable change source CR_FN9_SRC
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The alert log file reads:
Errors in file /oracle/DXCE/lvol11/background/dxce_j000_24285.trc:
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ORA-06550: line 1, column 96:
PLS-00201: identifier 'SYS.DBMS_CDC_PUBLISH' must be declared
ORA-06550: line 1, column 96:
PL/SQL: Statement ignored
Fri Mar 9 11:50:51 2007
Streams APPLY A002 started with pid=23, OS id=24304
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Streams Apply Server started P001 with pid=25 OS id=24308
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With the Partitioning, OLAP and Data Mining options
ORACLE_HOME = /oraxcd/10.2.0.3
System name: SunOS
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Release: 5.10
Version: Generic_118833-24
Machine: sun4v
Instance name: DXCE
Redo thread mounted by this instance: 1
Oracle process number: 29
Unix process pid: 24285, image: oracle@stwu01 (J000)
*** ACTION NAME:() 2007-03-08 14:57:15.007
*** MODULE NAME:() 2007-03-08 14:57:15.007
*** SERVICE NAME:(SYS$USERS) 2007-03-08 14:57:15.007
*** CLIENT ID:() 2007-03-08 14:57:15.007
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*** 2007-03-08 14:57:15.007
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ORA-06550: line 1, column 96:
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ORA-06550: line 1, column 96:
PL/SQL: Statement ignored
Regards,
Edosa

Can you help me about change data captures in 10.2.0.3

Hi,
I made research about Change Data Capture and I try to implement it between two databases for two small tables in 10g release 2.MY CDC implementation uses archive logs to replicate data.
Change Data Capture Mode Asynchronous autolog archive mode..It works correctly( except for ddl).Now I have some questions about CDC implementation for large tables.
I have one senario to implement but I do not find exactly how can I do it correctly.
I have one table (name test) that consists of 100 000 000 rows , everyday 1 000 000 transections occurs on this table and I archive the old
data more than one year manually.This table is in the source db.I want to replicate this table by using Change Data Capture to other stage database.
There are some questions about my senario in the following.
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3.How can I remove some data from change table(name test_ch) in stage db?It cause problem or not?
4.There is a way to replicate ddl operations between two database?
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6.How can I make the maintanence of change tables in stage db?

Asynchronous CDC uses Streams to generate the change records. Basically, it is a pre-packaged DML Handler that converts the changes into inserts into the change table. You indicated that you want the changes to be written to the original table, which is the default behavior of Streams replication. That is why I recommended that you use Streams directly.

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A couple of tips for using these procedures for downstream capture:
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 3) Explicitly define the parameters capture_queue_name and apply_queue_name to be the same queue name. Example:
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OWB Support for Change Data Capture

Hi All,
Has anyone got OWB working with the Change Data Capture feature in the Oracle 9i database? I understand that CDC works by publishing changes through an advanced queue, which in theory OWB 9.0.4 upwards can have as a data source, but there doesn't appear to be any explicit support within the GUI for capturing CDC changes.
I'm also working on the assumption that we're talking about Synchronous CDC as found in 9i. 10g comes with Asynchronous CDC which I guess presents a different interface to the receiving program.
So - is there any support for 9i Change Data Capture in OWB, and has anyone got this to work in practice?
thanks
Mark

Mark,
There is currently no explicit support for the 9i CDC. You can use Advanced Queues to propagate the changes, but you will have to custom-build the capture infrastructure on the source side (set up the CDC, enqueue the changes in the appropriate form into the AQ etc.)
OWB will explicitly support CDC (10g async, which is the least invasinve method) in our next major release currently scheduled to be release in November of this year.
Regards:
Igor

Change Data Capture: Unsubscribed column results in new change set record

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