ORA-01729: for XMLType

Question

Hi all,
i want to insert the xml data in my table with xmltype. At first i store these xml daten in another table as clob. But i get always the error message
ORA-01729: database link name expected
during the insert the xml data in xmltype column.
For the clobtable:
PreparedStatement pstmt_clob = con.prepareStatement("INSERT INTO clobtable VALUES(?, ?)");
pstmt_clob.setInt(1, f+1);
pstmt_clob.setCharacterStream(2, new java.io.FileReader(f_ordner[f+1]), (int)f_ordner[+1].length());
pstmt_clob.execute();
For the xmltable:
Connection conn = connect();
stmt.executeUpdate("UPDATE xmltable SET xml_dok = XMLTYPE.createXML(" + conn + "," + rs.getClob(2) + ")WHERE id =" + nr);
Code for connection:          
public Connection connect() throws Exception {
Class.forName("oracle.jdbc.OracleDriver");
Connection conn = DriverManager.getConnection(
"jdbc:oracle:oci:@zeus", "zhou", "diplom");
return conn;
I don't know, what's wrong with my programm. Can you help me?
thank you very much and greeting from germany
rabbit

Answer 1

I am not very experienced with JPA eclipselink, but I will try to answer the question since I think I know what the problem might be.
I think the problem is that you are storing the data in a String variable and sending it to the database as String(VARCHAR2). A variable of type VARCHAR2 can hold up to 4000 bytes of data (32K in PL/SQL, but this doesn't apply to you). Therefore if you try to store more than 4000 bytes you are in violation with this contract and thus ORA-01461 is thrown.
I think the right way to go is to use DirectToXMLTypeMapping. Have you tried that?
This link contains discussion that might be useful to you:
http://www.nabble.com/Oracle-XMLType,-JPA-and-EclipseLink-td19569909.html
Regarding the CHUNK size, it should be multiple of DB_BLOCK_SIZE parameter. For instance if this parameter in your database is set to 8192 (8K), then CHUNK size can be any of the following 8K, 16K, 24K and 32K (32K is the max allowed).
However, if you specify any other value for this parameter Oracle will automatically round it to the next (higher) multiple of DB_BLOCK_SIZE. In your case, if you use 8K blocks, this value will be 8192.
So there you should not be worried about this value at this point. I asked more out from curiosity.