Re: Problem with default partition pruning

At Tue, 09 Apr 2019 17:37:25 +0900 (Tokyo Standard Time), Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp> wrote in <20190409(dot)173725(dot)31175835(dot)horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp>
> > I'm attaching the latest version. Could you please check it again?

By the way, I noticed that partition constraint in a multi-level
partition contains duplicate clauses.

create table p (a int) partition by range (a);
create table c1 partition of p for values from (0) to (10) partition by range (a);
create table c11 partition of c1 for values from (0) to (2) partition by range (a);
create table c12 partition of c1 for values from (2) to (4) partition by range (a);

=# \d+ c12
| Partitioned table "public.c12"
| Column | Type | Collation | Nullable | Default | Storage | Stats target | De
| scription
| --------+---------+-----------+----------+---------+---------+--------------+---
| ----------
| a | integer | | | | plain | |
| Partition of: c1 FOR VALUES FROM (2) TO (4)
| Partition constraint: ((a IS NOT NULL) AND (a >= 0) AND (a < 10) AND (a IS NOT N
| ULL) AND (a >= 2) AND (a < 4))
| Partition key: RANGE (a)
| Number of partitions: 0

The partition constraint is equivalent to "(a IS NOT NULL) AND (a
>= 2) AND (a < 4)". Is it intentional (for, for example,
performance reasons)? Or is it reasonable to deduplicate the
quals?

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center