Re: REVIEW: EXPLAIN and nfiltered

* Tom Lane (tgl(at)sss(dot)pgh(dot)pa(dot)us) wrote:
> The main problem I've got with this patch is that there's no place to
> shoehorn the information into the textual EXPLAIN format without
> breaking a lot of expectations (and hence code --- it's insane to
> imagine that any significant amount of client-side code has been
> rewritten to make use of xml/json output yet). It would be nice to know
> what other requests are likely to be coming down the pike before we
> decide exactly how we're going to break things.

While I agree completely about the general "if you're going to break,
break it big" approach, but I don't particularly care for holding output
strings from EXPLAIN to the same level that we do the wireline protocol.
This is going into a new major version, not something which is being
back-patched, and users now have a way in a released version to get away
from relying on the string output.

Have we worried about adding new plan nodes due to breakage in the
explain output..? It strikes me that we've actually changed it with
some regularity, in one aspect or another, over a couple of releases.
Maybe my memory is bad though.

Thanks,

Stephen