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Connor McDonald

Thanks for the question, Shiva.

Asked: April 12, 2018 - 5:55 pm UTC

Last updated: April 14, 2018 - 3:47 am UTC

Version: 11.2 & 12.1

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You Asked

Hello,

We have a need to extract data using "sqoop" on a bunch of tables. However, there is no column defined in those tables that store information like "update date or last modified date". We are thinking of using ora_rowscn as a filter. However, the query always goes a full table scan.

Is there a way to avoid full table scan and still extract the incremental data?

Thanks,

and Connor said...

Nope.

By default the ora_rowscn is a block level recording anyway (not row level) so you might/will get rows extracted that were not actually updated.

Our general recommendation to pick up deltas is using Goldengate as a full replication/extraction solution.

If that is not an option (ie, $$$), then you'll need to look at some metadata to track changed rows (either additional columns or similar).

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Comments

Shiva, April 13, 2018 - 7:51 pm UTC

Thanks for the response. Is indexing ora_rowscn in Oracle's backlog?
Connor McDonald
April 14, 2018 - 3:47 am UTC

Not to my knowledge.

You could log it here

https://community.oracle.com/community/database/database-ideas


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