[Enterprise Extensions only]
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Oracle considerations

Large character data

The preferred Oracle data type for storing large character objects is CLOB. However, Oracle does not allow a CLOB to be queried. Because of this, a datatype of VARCHAR2 is used by BRBeans. A specific length must be specified when specifying VARCHAR2. The maximum length for a VARCHAR2 is 4000.

To determine the default size of VARCHAR2, look in the table.ddl file that was generated when you deployed the code. If the default size is not acceptable for your application, you can do one of the following:

  1. Increase the size of the columns.

    Keep in mind that maximum size for a VARCHAR2 in Oracle is 4000. Increase the column size either by changing the value in the create table statement, or by changing the schema mapping and deploying the BRBeans jar file.

  2. Change the schema mapping to specify CLOB

    Do this for any of the attributes that you do not wish to query, and then deploy the BRBeans jar file.

Isolation level

The default isolation level is REPEATABLE_READ. Oracle does not support this isolation level. Therefore, the Websphere runtime will convert this to the next highest isolation level, which in this case is SERIALIZED. Be aware that this isolation level tends to be overly restrictive, as it prevents two clients from reading data at the same time. The BRBeansOracle.jar file specifies an isolation level of READ_COMMITTED.

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