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

On Mon, Jul 31, 2017 at 9:07 AM, Ashutosh Bapat
<ashutosh(dot)bapat(at)enterprisedb(dot)com> wrote:
> Forgot the patch set. Here it is.

The commit message for 0005 isn't really accurate given that it
follows 0004. I think you could just flatten 0005 and 0006 into one
patch.

Reviewing those together:

- Existing code does partdesc = RelationGetPartitionDesc(relation) but
this has got it as part_desc. Seems better to be consistent.
Likewise existing variables for PartitionKey are key or partkey, not
part_key.

- get_relation_partition_info has a useless trailing return.

- Instead of adding nparts, boundinfo, and part_oids to RelOptInfo,
how about just adding partdesc? Seems cleaner.

- pkexprs seems like a potentially confusing name, since PK is widely
used to mean "primary key" but here you mean "partition key". Maybe
partkeyexprs.

- build_simple_rel's matching algorithm is O(n^2). We may have talked
about this problem before...

- This patch introduces some bits that are not yet used, like
nullable_pkexprs, or even the code to set the partition scheme for
joinrels. I think perhaps some of that logic should be moved from
0008 to here - e.g. the initial portion of
build_joinrel_partition_info.

There may be more, but I've run out of energy for tonight.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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