On Jul 5, 2009, at 10:02 AM, Gregory Stark <st...@mit.edu> wrote:
Here's a copy of the merge-append patch that I sent months ago
merged up to
head. I haven't really added any additional functionality since then.
Heikki suggested I separate the Append and MergeAppend nodes into
two executor
nodes. I had that half done in my tree but looking it over it leads
to a lot
of duplicated code and a strange effect that there's on Path node
but two
Executor nodes which seems strange. I'm not sure which way to go
here but at
least for now I'm leaving it this way since it's less code to write.
If we
want it the other way to commit then I'll do it.
The other pending question is the same I had back when I originally
submitted
it. I don't really understand what's going on with eclasses and what
invariants we're aiming to maintain with them. I don't see a problem
tossing
all the child relation attributes into the same eclass even though
they're not
strictly speaking "equivalent". No join above the append path is
going to see
the child attributes anyways. But that might be shortsighted as I'm
not really
sure what the consequences are and what other uses we have
envisioned for
eclasses in the future.
Can you provide some more details about the objective of this patch?
Or a link to previous discussion?
Thanks,
...Robert
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
