Change Data Capture
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Change Data Capture
Hi All,
We have a requirement where we have to capture changed data from a Sybase server. It is a Read Only server and everyday a SAN Snapshot (Backup) of the Production data is dumped in it (around 22 Million rows).
Not all tables have a As-of-Date or any such date field to be able to track the changes in data.
We have a load window constraint of around 6-7 hrs for capturing changed data and then loading it into the Sybase IQ Data Mart .
The Deltas should be in the range of 1,00,000 rows..(One hundred thousand)
So what is the best way to capture change in this scenario?
Can this be efficiently achieved via ETL , if yes, then how?
Thanks,
NV
We have a requirement where we have to capture changed data from a Sybase server. It is a Read Only server and everyday a SAN Snapshot (Backup) of the Production data is dumped in it (around 22 Million rows).
Not all tables have a As-of-Date or any such date field to be able to track the changes in data.
We have a load window constraint of around 6-7 hrs for capturing changed data and then loading it into the Sybase IQ Data Mart .
The Deltas should be in the range of 1,00,000 rows..(One hundred thousand)
So what is the best way to capture change in this scenario?
Can this be efficiently achieved via ETL , if yes, then how?
Thanks,
NV
Thanks DSGuru2B for your prompy response.
Is CDC plug-in stage available for ASE server (Sybase) and how does it achieve it?
Join stage, how would you achieve CDC using it?
Most importantly what is the impact on performance as we talking high volumes here?
Doing it at the DB level is not the option we have..it has to be implemented via ETL
Regards,
NV
Is CDC plug-in stage available for ASE server (Sybase) and how does it achieve it?
Join stage, how would you achieve CDC using it?
Most importantly what is the impact on performance as we talking high volumes here?
Doing it at the DB level is not the option we have..it has to be implemented via ETL
Regards,
NV
What is you version of datastage? ChangeCapture should be able to find the difference in the Input1 to the Input2. A flag used to indentify this change.
Full Outer Join coupled with Transformer with Null Detection can be used to construct the similar functionality.
If you have any timestamp field to denote the row updated timestamp, it should make your life more easy.
Full Outer Join coupled with Transformer with Null Detection can be used to construct the similar functionality.
If you have any timestamp field to denote the row updated timestamp, it should make your life more easy.
Impossible doesn't mean 'it is not possible' actually means... 'NOBODY HAS DONE IT SO FAR'
Thanks Kumar..
We are using 7.5.1 (Enterprise edition..Parallel).
As I have mentioned in my first post, we do not have the luxury of having date time fields..so life is going to be tough!!
We have implemented change data capture in another project..the volumes was pretty low there though.
My main area of concern is performance and the time taken for it.
Would request you guys to touch on that.
I have provided all data row counts in my first post.
Regards,
Nirav
We are using 7.5.1 (Enterprise edition..Parallel).
As I have mentioned in my first post, we do not have the luxury of having date time fields..so life is going to be tough!!
We have implemented change data capture in another project..the volumes was pretty low there though.
My main area of concern is performance and the time taken for it.
Would request you guys to touch on that.
I have provided all data row counts in my first post.
Regards,
Nirav
Kumar,
There are no predefined rules for capturing teh changes..that is the challenge.
Back up of the entire Production DB is taken on the Sybase server (source for our ETL process) every 12 hrs..so we have to capture only the changes in betwen these 2 back ups and the load in the target Sybase IQ server. We do not touch the Prod server at all.
Refer to first post..
Regards,
NV
There are no predefined rules for capturing teh changes..that is the challenge.
Back up of the entire Production DB is taken on the Sybase server (source for our ETL process) every 12 hrs..so we have to capture only the changes in betwen these 2 back ups and the load in the target Sybase IQ server. We do not touch the Prod server at all.
Refer to first post..
Regards,
NV
Okey.... Key for the each table (Backup for two consecutive days) should be marked as Key in Chane Capture and Preferred field can be marked as data or optionally All fields can be marked as Data field in Chagne capture.
But capturing changes based on Database log should be more faster. Not sure, why you refrain to use Database for this.
But capturing changes based on Database log should be more faster. Not sure, why you refrain to use Database for this.
Impossible doesn't mean 'it is not possible' actually means... 'NOBODY HAS DONE IT SO FAR'
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