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Anonymous
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Change Data Capture, how it works in Talend?

I have read Talend has change data capture. Can you please describe in details:
1) how it works
2) do you support Oracle in particular and may be a DB2 as a source?
3) Is it a log-based, meaning read transaction logs or have a trigger based mechanism
The reference to documentation would be helpful
Thanks,
Mike
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32 Replies
Anonymous
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Author

Anybody can answer this question?
Thanks,
Mike
Anonymous
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Author

Hello,
1) How it works :
Change Data Capture (CDC) is based on Publisher/Subscriber principle. The publisher captures the change data and makes it available to the subscribers. The subscribers can use the change data obtained from the publisher only once. To be able to use a given number of times the same change data, you should use as many differents subscribers. The informations about source tables from which the change data needs to be captured and the subscribers who can access to the change data are stored in a TSUBSCRIBER table. The TCDC_source_table contains the id of each change data. The triggers TCDC_TG_source_table_I, TCDC_TG_source_table_U and TCDC_TG_source_table_D are created to capture each Insert, Update and Delete on source_table. Each change row capture by the triggers is inserted into TCDC_source_table with the flag TALEND_CDC_STATE='0'. Before consuming the row, this flag is set to TALEND_CDC_STATE='1' and a view TCDC_VIEW_source_table is create or replace to fetch rows from source table and only rows with TALEND_CDC_STATE='1'. This allows you to lock the lines to consum and to delete it after consuming where SUBSCRIBER = the subscriber you have to consum the change data.
2) do you support Oracle in particular and may be a DB2 as a source?
CDC is available in Java for Oracle, MySQL, DB2, PostgreSQL, Sybase, and MS SQL Server databases.
3) Is it a log-based, meaning read transaction logs or have a trigger based mechanism
CDC have a trigger based mechanism
Thanks, 0683p000009MACn.png
Anonymous
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Author

Do you know which SQL Sever version is needed to work with Talend CDC?
I mean 2000? 2005? 2008? Standard? Enterprise?
Anonymous
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Author

Hello
Do you know which SQL Sever version is needed to work with Talend CDC?

All version should be supported, if you have any problem, please report a bug and it is necessary for us to fix it.
Best regards
Shong
Anonymous
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Author

publisher captures the change data and makes it available to the subscribers. The subscribers can use the change data obtained from the publisher only once.
Anonymous
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Author

Hello,
In databases, change data capture (CDC) is a set of software design patterns used to determine (and track) the data that has changed so that action can be taken using the changed data. Also, Change data capture (CDC) is an approach to data integration that is based on the identification, capture and delivery of the changes made to enterprise data sources.
CDC solutions occur most often in data-warehouse environments since capturing and preserving the state of data across time is one of the core functions of a data warehouse, but CDC can be utilized in any database or data repository system.
Anonymous
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Author

Hello, everybody!
I have been searching for CDC function in SQL Server.
Could you please help me, I want to know about the following information
(1) CDC mechanism in talend
>3) Is it a log-based, meaning read transaction logs or have a trigger based mechanism
>CDC have a trigger based mechanism
It means All of the databases on talend have a trigger based mechanism to implement CDC.
(2) Can you show the way how to implement Change Data Capture in SQL Server?
Regards
Lee,
Anonymous
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Author

Hi Lee
Welcome to Talend Community!
As the user of Talend Integartion Suite(Commercial edition), you can get instructions and scenarios in the document ->Chapter 10:Change Data Capture.
Regards,
Pedro
Anonymous
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Author

Hi, pedro!
Thank you a lot for your tips.
I contacted Ashisuto company in Japan.
and they will give me a demo to show the CDC(Change Data Capture) function on SQL Server 2000.
Best Regrads,
Lee