DDL for PostgreSQL for DB2 tables (migration)
BLOB should be translated to bytea in Postgres and CLOB to text. 

DECIMAL(15) is probably better done as bigint and char() should not be used at all. I would replace that with varchar(30) 

I don't know what rowid is in DB2. 

The with default option is invalid for Postgres. If you want a default value you need to specify it explicitly, e.g.: 

field_6  INTEGER       NOT NULL DEFAULT 42,