Doubt handling Clob columns with Java JDBC api

Question

Hi,
we have a doubt handling Clob columns with Java JDBC api.
Reading Oracle 10g official documentation (document b10979.pdf, page 236), we found this note:
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To write LOB data, the application must acquire a write lock on the LOB object. One way to accomplish this is through a SELECT FOR UPDATE. Also, disable auto-commit mode.
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We also found a java sample code about how to handle Lob objects at this URL:
http://www.oracle.com/technology/sample_code/tech/java/sqlj_jdbc/files/advanced/LOBSample/LOBSample.java.html
In our java2 application, we access Clob objects in a quite different
manner: we use normal setString() and getString() methods, as described into paragraph "Shortcuts For Inserting and Retrieving CLOB Data"
(document b10979.pdf, page 244).
Using those methods, we never lock the table row by a SELECT FOR UPDATE statement (as described into the note above). We use simply SELECT, UPDATE and INSERT prepared statement.
In this way we can insert both clob objects and normal timestamp, number and other types with a single insert statement. Idem for update.
To recap, our question is:
Is it mandatory to create a SELECT FOR UPDATE statement when updating clob data? What may be the consequences if we don't use it? It is also correct to insert with a single sql statement both clob and not clob data using the setString() method for the clob types? And more than one lob column in the same record?
bye,
luca acri.

Answer 1

And columns of type FLOAT. These also have, for some unknown reason a metadata type of OTHER, and a type string of 'FLOAT'. Yet PreparedStatement.setNull(x, Types.OTHER) doesn't work and setNull(x, Types.DECIMAL) does.