It has been verified that if import uses the following URL property

useFetchSizeWithLongColumn=true 

it significantly improves the metadata load process, especially when there are a large number of tables in a schema. See doc [1]

Teiid should either somehow enforce or document this.

[1] https://docs.oracle.com/cd/E11882_01/appdev.112/e13995/oracle/jdbc/OracleDriver.html