Oracle Loader For Hadoop Is Not Compressing Data Using Online Mode between Exadata 220.127.116.11.0 and BDA 2.3.1
Last updated on OCTOBER 28, 2014
Applies to:Oracle Loader for Hadoop - Version 2.3.1 and later
On BDA 2.3.1 with OLH 2.3.0, how is compressing data in online mode supported?
When using Oracle Loader for Hadoop (OLH) in online mode, that is, inserting directly into Oracle tables (Exadata included) from Hive tables, data is inserted without any compression, even if before the insertion ALTER TABLE ..... COMPRESS FOR QUERY is performed.
The default value of the property oracle.hadoop.loader.compressionFactors does not appear to cause compression either:
Default Value: BASIC=5.0,OLTP=5.0,QUERY_LOW=10.0,QUERY_HIGH=10.0,ARCHIVE_LOW=10.0,ARCHIVE_HIGH=10.0
Is the correct expectation that OLH uses the following hint?
INSERT /*+ APPEND_VALUES */ INTO VALUES().
According to the documentation in the Oracle Big Data Connectors User's Guide Release 2(2.4), Section: 3.14 Oracle Loader for Hadoop Configuration Property Reference, it appears that this should work.
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