View parsing

Hi all,

I would like to be able to determine which tables each field of a view
comes from.

I have a view definition like
  SELECT tbl_a.fld_a, tbl_b.fld_b AS fld_e, function(c,d,f) as fld_c,
(SELECT fld_d FROM tbl_d WHERE tbl_d.fld_e=tbl_a.fld_a) as fld_d FROM
tbl_a inner join tbl_b on tbl_a.fld_e=tbl_b.fld_f WHERE cond_a;

What I'd like to get to is a list of fields in the view indicating how
each is calculated - without putting the definition into a horrible bunch
of regexps. (Which would no doubt work but seems the wrong thing to do.)

Something like this would be ideal:

fld_a -> tbl_a.fld_a
fld_e -> tbl_b.fld_b
fld_c -> function(c,d,f)
fld_d -> (SELECT fld_d FROM tbl_d WHERE tbl_d.fld_e=tbl_a.fld_a)

My goal is to answer the question "in what other views might I find the
data which I see as, say, fld_e?". Once I know where the data comes from I
can dig through the pg_depends data and figure out other views which
depend on that (table,column) tuple and go from there.

Yours,

Frank