Re: debugging query to put message in pg logfile?

On Thu, 04 Mar 2004 16:35:01 -0500
Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> threw this fish to the penguins:

> george young <gry(at)ll(dot)mit(dot)edu> writes:
> > I've started putting debugging queries like:
> > select "opwin.py: committing step signoff"
> > in my app, just to have an entry in the postgres logfile.
>
> > Is there some cheaper (or more appropriate) sql statement that will show
> > up in the postgres log?
>
> You could just send SQL comments:
>
> -- opwin.py: committing step signoff
>
> One advantage of this is that you can merge the comments with actual
> commands, thus not incurring even a network round-trip time for them.
> If you do send it separately, it will act like an empty query string.
>
> People tend not to think of this because psql strips -- comments before
> sending commands. But I believe all the lower-level libraries will pass
> them through. (If you need to pass loggable comments through psql, I
> think the /* ... */ form will work.)

Alas no:

Python 2.3.3 (#1, Jan 3 2004, 07:17:11)
[GCC 3.3.2] on linux2
>>> import pgdb
>>> db=pgdb.connect(host='ivy:5433',database='pigtest')
>>> c=db.cursor()
>>> cur.execute('-- the rain')
Traceback (most recent call last):
File "<stdin>", line 1, in ?
File "/usr/local/lib/python2.3/site-packages/pgdb.py", line 189, in execute
self.executemany(operation, (params,))
File "/usr/local/lib/python2.3/site-packages/pgdb.py", line 210, in executemany
raise OperationalError, "internal error in '%s'" % sql
pgdb.OperationalError: internal error in '-- the rain'

Likewise for /* comments */. :-(

I'll continue this on the pygresql mailing list; and I guess stick to
"select 'comment text'" for now...

Thanks,

-- George Young

--
"Are the gods not just?" "Oh no, child.
What would become of us if they were?" (CSL)