I am getting the below error , when i am trying to deploy pega 7.1.7 in oracle database , win 7 os.

[java] --
     [java] -- Name: pr_read_from_stream
     [java] --
     [java] -- Description:
     [java] --
     [java] language java
     [java] name 'com.pega.pegarules.data.udf.directstreamreader.DirectStreamReader.get(java.lang.String, java.lang.String, java.sql.Blob) return java.lang.String';
     [java] java.sql.SQLSyntaxErrorException: ORA-00955: name is already used by an existing object
     [java]
     [java]  at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:447)
     [java]  at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:396)
     [java]  at oracle.jdbc.driver.T4C8Oall.processError(T4C8Oall.java:951)
     [java]  at oracle.jdbc.driver.T4CTTIfun.receive(T4CTTIfun.java:513)
     [java]  at oracle.jdbc.driver.T4CTTIfun.doRPC(T4CTTIfun.java:227)
     [java]  at oracle.jdbc.driver.T4C8Oall.doOALL(T4C8Oall.java:531)
     [java]  at oracle.jdbc.driver.T4CStatement.doOall8(T4CStatement.java:195)
     [java]  at oracle.jdbc.driver.T4CStatement.executeForRows(T4CStatement.java:1036)
     [java]  at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:1336)
     [java]  at oracle.jdbc.driver.OracleStatement.executeInternal(OracleStatement.java:1916)
     [java]  at oracle.jdbc.driver.OracleStatement.execute(OracleStatement.java:1878)
     [java]  at oracle.jdbc.driver.OracleStatementWrapper.execute(OracleStatementWrapper.java:318)
     [java]  at com.pega.pegarules.install.SQLLoader.main(SQLLoader.java:298)
     [java] May 28, 2015 12:17:34 PM com.pega.pegarules.install.SQLLoader writeMessage
     [java] INFO:
     [java] ********************************************************************************
     [java]
     [java] Encountered a SQL Exception, clean schema before running again.
     [java]
     [java] ********************************************************************************