Re: BUG #6513: explain (analyze, buffers) and toasted fields

On Mon, Mar 12, 2012 at 17:23, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> EXPLAIN ANALYZE *necessarily* does less work than the real query,
> because it doesn't transmit the results to the client (which is going
> to be a dominant cost in a lot of situations).  I'm not sure whether
> running the I/O functions would provide a useful improvement in
> verisimilitude or not

Granted, but I can see how one would expect the detoasting to be
accounted for in EXPLAIN, since it's something that's usually done
*inside* the database (as opposed to network overhead). That would
give a more accurate picture of where the time is being spent.

Now, another question is whether to use text or binary output
functions. And where to account the time, since this happens outside
of the plan tree.

At the very least, I think this gotcha should be documented on the EXPLAIN page.

Regards,
Marti