Are these supported??

Hi all, been awhile! Some may be saying "not long enough" but eh.

I recently moved a mybb forum away from mysql to postgres. Along the way
I encountered a couple of things that either didn't seem to be supported
or I'm just not doing it right.

First, the server this is on is running version 8.4.22. php is 5.6.22.

#1 Are joins supported in deletes? The same join syntax works fine as
a select.

#2 is extract supported in a select statement dealing with a table? To
explain this one, here is the error I get:

# select date_part('epoch', dateline) from mybb_adminlog limit 1;ERROR:
function date_part(unknown, integer) does not exist
LINE 1: select date_part('epoch', dateline) from mybb_adminlog limit...
^
HINT: No function matches the given name and argument types. You might
need to add explicit type casts.
#

or ...

# select extract(epoch from timestamp dateline::timestamp) from
mybb_adminlog limit 1;
ERROR: syntax error at or near "dateline"
LINE 1: select extract(epoch from timestamp dateline::timestamp) fro...
#

Doesn't matter if I use epoch or day or anything else, they all fail with
the same error. And yes, dateline is a timestamp. WITH or WITHOUT
timezone made no difference.

So my questions are..

Does Postgres not support joins in deletes?

If not, is there a reason?

Is EXTRACT and/or date_part not supported in select calls where a table is
involved?

If not, is there a reason or a work around for selecting the epoch of a
timestamp?

Thanks!!! Miss you guys!!!
Vince.