enable EXTRACT EPOCH/QUARTER from timestamp

I am connecting to Teiid from Tableau using the JDBC driver and PostgreSQL dialect. I try to drill into a timestamp field, and I get some complaints parsing the SQL. In particular, it has trouble with:

EXTRACT(QUARTER FROM the_time)
EXTRACT(EPOCH FROM the_time)

The docs suggest these datetime components are not supported by Teiid. They are not standard, but supporting them would get me a step closer to running Tableau against Teiid (a killer app!)

I was able to work around the QUARTER by dismissing the error, drilling down to month, dismissing the error again, then dragging the quarter out of my drill-down.

I worked around the EPOCH by moving a date difference from being calculated in Tableau to calculating it in Teiid with TIMESTAMPDIFF.

An alternate I tried was using Tableau's SQL92 dialect, but it issues a "SELECT TOP" clause that is not SQL92 standard and also not supported by Teiid.