Re: Partition-wise join for join between (declaratively) partitioned tables

On Thu, Sep 21, 2017 at 8:21 AM, Ashutosh Bapat
<ashutosh(dot)bapat(at)enterprisedb(dot)com> wrote:
> Here's set of rebased patches. The patch with extra tests is not for
> committing. All other patches, except the last one, will need to be
> committed together. The last patch may be committed along with other
> patches or as a separate patch.

In set_append_rel_size, is it necessary to set attr_needed =
bms_copy(rel->attr_needed[index]) rather than just pointing to the
existing value? If so, perhaps the comments should explain the
reasons. I would have thought that the values wouldn't change after
this point, in which case it might not be necessary to copy them.

Regarding nomenclature and my previous griping about wisdom, I was
wondering about just calling this a "partition join" like you have in
the regression test. So the GUC would be enable_partition_join, you'd
have generate_partition_join_paths(), etc. Basically just delete
"wise" throughout.

The elog(DEBUG3) in try_partition_wise_join() doesn't follow message
style guidelines and I think should just be removed. It was useful
for development, I'm sure, but it's time for it to go.

+ elog(ERROR, "unrecognized path node type %d", (int) nodeTag(path));

I think we should use the same formulation as elsewhere, namely
"unrecognized node type: %d". And likewise probably "unexpected join
type: %d".

partition_join_extras.sql has a bunch of whitespace damage, although
it doesn't really matter since, as you say, that's not for commit.

(This is not a full review, just a few thoughts.)

--
Robert Haas
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