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https://issues.apache.org/jira/browse/SQOOP-3022?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15555869#comment-15555869
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Ruslan Dautkhanov commented on SQOOP-3022:
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It's not only a syntax sugar, it allows to save you a lot on network roundtrips.
For example, to insert 1000 records, Sqoop currently has to actually make 1000
database execute calls for each record.
With INSERT ALL - you make one(1) call to insert all 1000 records.
Let's say network latency between hadoop server that runs sqoop and your
database server is 3ms.
So to insert above 1000 records it takes 3 seconds in this case with record by
record processing (3ms x 1000).
So you need fewer sqoop mappers to provide the same records/second throughput.
Fewer sessions => less contention and less opportunity to catch issues like
ORA-12838 above.
Does it make sense?
> sqoop export for Oracle generates tremendous amounts of redo logs
> -----------------------------------------------------------------
>
> Key: SQOOP-3022
> URL: https://issues.apache.org/jira/browse/SQOOP-3022
> Project: Sqoop
> Issue Type: Bug
> Components: codegen, connectors, connectors/oracle
> Affects Versions: 1.4.3, 1.4.4, 1.4.5, 1.4.6
> Reporter: Ruslan Dautkhanov
> Labels: export, oracle
>
> Sqoop export for Oracle generates tremendous amounts of redo logs (comparable
> to export size or more).
> We have put target tables in nologgin mode, but Oracle will still generate
> redo logs unless +APPEND Oracle insert hint is used.
> See https://oracle-base.com/articles/misc/append-hint for examples.
> Please add an option for sqoop to generate insert statements in Oracle with
> APPEND statement. Our databases are swamped with redo/archived logs whenever
> we sqoop data to them. This is easily avoidable. And from business
> prospective sqooping to staging tables in nologgin mode is totally fine.
> Thank you.
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