Index Table DB datatype for String fields


I am currently having the following problem related to the Indexed Task Search.

Basically I have a field that is indexed and that is the concatenation of some values.

When I try to add more to the field and update the task, the following happens:

SOAPException( Server.userException: com.webmethods.portal.bizPolicy.BizException: [POP.001.0002] A "java.sql.SQLException" occurred with the Message "[SoftwareAG][SQLServer JDBC Driver][SQLServer]Operation failed. The index entry of length 922 bytes for the index INDEX_T_TASK_I_5BE8900839_FIELD_23 exceeds the maximum length of 900 bytes." )

Now, the message is clear. An indexed field cannot have more the 900 bytes.

When I indexed my field, I set his value to be String, which, when the indexed table was dynamically created translated into DB type nvarchar.

The storage for nvarchar is the following: “The storage size, in bytes, is two times the actual length of data entered + 2 bytes.”

Which basically means that I am allowed to have only 449 character in my field for this to function.

My question is:

Is there a way to instruct the Task Engine to create the filed as simple varchar?

Do you have any other ideas?

Best regards,
Vlad Turian