pl help for the foollowing query it throws exception

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query
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String HQL="from HelpdeskArticles n where lower(n.title) like :searchText or lower(n.description) like :searchText and

newsList=session.createQuery(HQL).setParameter("searchText","%"+searchFilter.getSearchText().toLowerCase()+"%").

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exception
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org.hibernate.exception.SQLGrammarException: could not execute query

com.ibm.db2.jcc.b.SqlException: No authorized routine named "UPPER" of type "FUNCTION" having compatible arguments was found.

The DB column data type for description is CLOB , can't we apply lower() function for CLOB type column