On 29 March 2018 at 21:35, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp> wrote:
> Beside fixing that, I have decided to get rid of the
> PartititionPruneStepOpNe (a special kind of base pruning step that was
> being used to prune list partitions using a set of <> operator clauses)
> and related functions. Instead pruning for <> operator clauses is now
> implemented by using a combination of PartitionPruneStepOp and
> PartitionPruneStepCombine after adding a new combine op COMBINE_INVERT (I
> also renamed COMBINE_OR and COMBINE_AND to COMBINE_UNION and
> COMBINE_INTERSECT, respectively). I decided to do so because the previous
> arrangement looked like a "hack" to support a special case that touched no
> less than quite a few places.
Hi Amit,
I've looked at the v44 patch. Thanks for making those changes.
The new not-equal handling code is not quite right.
DROP TABLE listp;
CREATE TABLE listp (a INT) PARTITION BY LIST(a);
CREATE TABLE listp1_3 PARTITION OF listp FOR VALUES IN(1,3);
CREATE TABLE listp_default PARTITION OF listp DEFAULT;
EXPLAIN SELECT * FROM listp WHERE a <> 1;
QUERY PLAN
------------------------------------------------------------------
Append (cost=0.00..54.56 rows=2537 width=4)
-> Seq Scan on listp1_3 (cost=0.00..41.88 rows=2537 width=4)
Filter: (a <> 1)
(3 rows)
The default should be included here.
INSERT INTO listp VALUES(1),(2),(3);
SELECT * FROM listp WHERE a <> 1;
a
---
3
(1 row)
This code assumes its fine to just reverse the setting for default:
result->scan_default = !source->scan_default;
More complex handling is needed here.
I've attached a diff for a small set of other things I noticed while reviewing.
--
David Rowley http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
