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https://issues.apache.org/jira/browse/SQOOP-3022?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15553578#comment-15553578
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Ruslan Dautkhanov commented on SQOOP-3022:
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You're right on APPEND_VALUES hint. Thank you for pointint to that [~maugli]
I just ran a few small tests with this hint on row by row inserts
and managed to get "ORA-12838: cannot read/modify an object after modifying it
in parallel"
on one of inserts. So there is some scalability problems with this hint.
It may still work if you don't have long-living transactions (i.e. set
-Dsqoop.export.statements.per.transaction=1 but tune up well
-Dsqoop.export.records.per.statement ?).
On a side note, have you looked at Oracle's INSERT ALL command when you can
specify multiple rows in one INSERT statement?
See for example https://www.techonthenet.com/oracle/questions/insert_rows.php
"INSERT ALL" is supported since at least Oracle 10g -
https://docs.oracle.com/cd/B19306_01/server.102/b14200/statements_9014.htm so
it should not new feature, and shouldn't be a compatibility concern. INSERT ALL
with APPEND_VALUES hint may play better in terms of scalability.
> 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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