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Performance-Problem With Nclob-Fields With Oracle 10g And WebLogicServer (Doc ID 874379.1)

Last updated on MAY 07, 2020

Applies to:

Oracle WebLogic Server - Version 8.1 to 10.3.1
Information in this document applies to any platform.


There is a performance problem which is related to the storing of foreign-language texts (e.g. thai) in NCHAR columns in Oracle Database 10g. Using CMP with Oracle 10g and has NClob column in DB, WLS has to use system property -Doracle.jdbc.defaultnchar=true.

This flag is document within the Oracle Database documentationed

Once this value is set, any database requests now lasts for a much extended period of time, in the case that was seen, queries took approximately 5 minutes instead of the expected 2 seconds before the property was set. This is because, after the property was set to true, a full table scan is being executed instead of a query using the primary key.


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