When using 'OPTION NOCACHE' in a query, there are probably still cached results for the query.
The tested query:

/*+ cache */ SELECT * FROM Customers OPTION NOCACHE

Test scenario:
Insert value into db, directly through its jdbc driver:

INSERT INTO Customers VALUES(1, 'name1')

Check via teiid, that query returns one row. This result set should not be cached.

/*+ cache */ SELECT * FROM Customers OPTION NOCACHE

Insert another row into db, via its jdbc driver, not through teiid:

INSERT INTO Customers VALUES(2, 'name2')

Check that this query returns again current state of db (2 rows) now:

/*+ cache */ SELECT * FROM Customers OPTION NOCACHE

But this check fails, teiid returns only one row, seemingly the result set for query with 'OPTION NOCACHE' gets cached.