Horton

RE: speeding up planning with partitions

Imai, Yoshikazu <imai.yoshikazu@jp.fujitsu.com>

View thread View on postgr.es
From: "Imai, Yoshikazu" <imai.yoshikazu@jp.fujitsu.com>
To: 'Amit Langote' <Langote_Amit_f8@lab.ntt.co.jp>
Cc: Imai Yoshikazu <yoshikazu_i443@live.jp>, "jesper.pedersen@redhat.com" <jesper.pedersen@redhat.com>, 'Amit Langote' <amitlangote09@gmail.com>, "David Rowley" <david.rowley@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>, "Alvaro Herrera" <alvherre@2ndquadrant.com>, Robert Haas <robertmhaas@gmail.com>, Justin Pryzby <pryzby@telsasoft.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2019-03-26T10:02:55Z
Lists: pgsql-hackers 
Amit-san,

On Tue, Mar 26, 2019 at 7:17 AM, Amit Langote wrote:
> Rebased patches attached.

I could only do the code review of v36-0001.

On Mon, Mar 25, 2019 at 11:35 AM, Amit Langote wrote:
> On 2019/03/23 6:07, Tom Lane wrote:
> > Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> writes:
> >> [ v34 patch set ]
> > 
> > I had a bit of a look through this.  I went ahead and pushed 0008 and
> > 0009, as they seem straightforward and independent of the rest.  (BTW,
> > 0009 makes 0003's dubious optimization in set_relation_partition_info
> > quite unnecessary.)  As for the rest:
> > 
> > 0001: OK in principle, but I wonder why you implemented it by adding
> > another recursive scan of the jointree rather than just iterating
> > over the baserel array, as in make_one_rel() for instance.  Seems
> > like this way is more work, and more code that we'll have to touch
> > if we ever change the jointree representation.
> 
> I've changed this to work by iterating over baserel array.  I was mostly
> worried about looping over potentially many elements of baserel array that
> we simply end up skipping, but considering the other patch that delays
> adding inheritance children, we don't need to worry about that.
>
> > I also feel like you used a dartboard while deciding where to insert the
> > call in query_planner(); dropping it into the middle of a sequence of
> > equivalence-class-related operations seems quite random.  Maybe we could
> > delay that step all the way to just before make_one_rel, since the other
> > stuff in between seems to only care about baserels?  For example,
> > it'd certainly be better if we could run remove_useless_joins before
> > otherrel expansion, so that we needn't do otherrel expansion at all
> > on a table that gets thrown away as being a useless join.
> 
> create_lateral_join_info() expects otherrels to be present to propagate
> the information it creates.
> 
> I have moved add_other_rels_to_query() followed by
> create_lateral_join_info() to just before make_one_rel().

I checked 0001 patch modifies the thing which is discussed above correctly.

What problem I only found is a little typo.
s/propgated/propagated/

I'm really sorry for my shortage of time to review for now...

--
Yoshikazu Imai

Commits

  1. Clean up handling of constraint_exclusion and enable_partition_pruning.

  2. Add test case exercising formerly-unreached code in inheritance_planner.

  3. Speed up planning when partitions can be pruned at plan time.

  4. Avoid crash in partitionwise join planning under GEQO.

  5. Avoid passing query tlist around separately from root->processed_tlist.

  6. Build "other rels" of appendrel baserels in a separate step.

  7. Get rid of duplicate child RTE for a partitioned table.

  8. Rearrange make_partitionedrel_pruneinfo to avoid work when we can't prune.

  9. Don't copy PartitionBoundInfo in set_relation_partition_info.

  10. Move building of child base quals out into a new function

  11. Reorganize planner code moved in b60c39759908

  12. Move inheritance expansion code into its own file

  13. Fix inherited UPDATE/DELETE with UNION ALL subqueries.

  14. Rearrange planner to save the whole PlannerInfo (subroot) for a subquery.