Re: Access to postgresql query optimizer output

On Mon, Oct 29, 2012 at 1:07 AM, Seref Arikan
<serefarikan@kurumsalteknoloji.com> wrote:
> Greetings,
> I keep seeing statements like "Postgresql optimizer rewrites this query
> as...." What I'm curious about is, is there a way to obtain SQL form of the
> re-written queries somewhere in the chain of query evaluation? It does not
> make a lot sense to generate sql again, but it would help a lot to see  the
> queries in their  rewritten form.

The re-writing does not occur at the level of SQL, but rather at the
level of an internal representation "parse tree".

You can see these representations using these configuration settings;

debug_print_parse = on
debug_print_rewritten = on

I'm not aware of anything that turns those back into SQL.

Cheers,

Jeff