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
