Sun Java System Application Server Platform Edition 9 Developer's Guide

Database Restrictions and Optimizations

This section discusses restrictions and performance optimizations that affect using the Java Persistence API.

Using BLOB or CLOB Types with the Inet Oraxo JDBC Driver

To use BLOB or CLOB data types larger than 4 KB for persistence using the Inet Oraxo JDBC Driver for Oracle Databases, you must set the database's streamstolob property value to true.

Case Insensitivity of Field Names

In the Application Server, schema generation converts all field names to uppercase. Therefore, if you are using a case sensitive database, make sure all field names in the code and the database are in uppercase.

Using a SERIAL Field in PostgreSQL

To use a SERIAL field in a PostgreSQL database, define the following in your entity class:


The field created is of type SERIAL, and the implicit native sequence associated with this field is of the form FullyQualifiedName_IdFieldColumnName_SEQ.

Sybase Finder Limitation

If a finder method with an input greater than 255 characters is executed and the primary key column is mapped to a VARCHAR column, Sybase attempts to convert type VARCHAR to type TEXT and generates the following error:

com.sybase.jdbc2.jdbc.SybSQLException: Implicit conversion from datatype 
'TEXT' to 'VARCHAR' is not allowed.  Use the CONVERT function to run this 

To avoid this error, make sure the finder method input is less than 255 characters.

MySQL Database Restrictions

The following restrictions apply when you use a MySQL database with the Application Server for persistence.