Re: EXPLAIN Node Docs?

On Apr 29, 2011, at 2:07 PM, Tom Lane wrote:

> In particular, src/include/nodes/plannodes.h is pretty well commented.

Ah, that's a useful file to scan, thanks.

> If it's not immediately obvious how that maps to what's shown by
> EXPLAIN, look into commands/explain.c.

Yeah, that's the file I have been reading.

> (There are things that aren't
> mentioned by EXPLAIN even in verbose mode, such as which columns Group
> is going to group by; usually that's because it's redundant with info
> available elsewhere, such as the sort columns of a lower sort node.)

Right, I figured that one out. Same does not appear to be true of Filter elements, though.

> Keep in mind also that we reserve the right to whack these things around
> in arbitrary ways from one release to the next.

Yeah, though I assume you mean major releases, not maintenance releases. Still, it'd be nice to have a documentation reference.

Best,

David