Using BLOBs with several DBMS

Hi,


I'm trying to make a application in JAVA that connects thought JDBC to DBMS. 
It should create tables, insert data and make queries.

My question is: how can i create a table with one BLOB field, in a DBMS 
independent way?

I am using PostgreSQL7.1 and Oracle 8 but I want to make it be able to work 
with other DBMSs.


Thanks

Ricardo Maia