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https://issues.apache.org/jira/browse/SQOOP-3022?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15566863#comment-15566863
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Attila Szabo commented on SQOOP-3022:
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Hi [~Tagar],
I think for this related problem had the designers created the
PreparedStatement interface (
https://docs.oracle.com/javase/7/docs/api/java/sql/PreparedStatement.html ) in
the JDBC API and generally batching ( see addBatch and executeBatch methods on
both PreparedStatement and Statement interfaces ).
I'm not 100% sure (because it's been a while I'd dig deep into Oracle's
proprietary JDBC driver through a decompiler) but I do think every batch
execute is doing only 1 network roundtrip + AFAIR JDBC is also supporting
compression over the network.
Especially in case of Sqoop we're depending on JDBC PreparedStatement batching
functionality.
So I think in our current case it would not much matter, if we would
concatenate all the statements as String on Java side and send out one query,
or rather with the help of PreparedStatement we would be able to send it out as
a batch (and AFAIR PreparedStatement could be cached on Oracle side, so even
query parsing is cheaper, but I'm not sure if it's true all the cases, or just
in case of named params).
What do you think? Do you still have concerns and suggesting the usage INSERT
ALL statements?
Thanks,
[~maugli]
> 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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