PHP & PostgreSQL

I'm switching from a MySQL environment to PGSQL and I'm
going through and trying to learn the differences between the
two.  I've come across some issues that I can't seem to find the
answers to in the docs or on the web.  I'm hoping someone can
help me out.

* MySQL has a function to reset the result set so that it can be
iterated through again - mysql_data_seek().  I don't see that there
is a similar function for PGSQL.  Is that true?  If so, in order to
reset the result set you have to perform the query again?  Isn't
that a waste of resources?

* For PGSQL, you can get the database name, the field name
even the *host name* but you can't get the table name from a
particular query?

Any info would be greatly appreciated!

Chris