why partition pruning doesn't work?

Hi

CREATE TABLE data(a text, vlozeno date) PARTITION BY RANGE(vlozeno);
CREATE TABLE data_2016 PARTITION OF data FOR VALUES FROM
('2016-01-01') TO ('2016-12-31');
CREATE TABLE data_2017 PARTITION OF data FOR VALUES FROM
('2017-01-01') TO ('2017-12-31');
CREATE TABLE data_other PARTITION OF DATA DEFAULT;

insert into data select 'ahoj', '2016-01-01'::date + (random() *
900)::int from generate_series(1,1000000);
analyze data;

postgres=# explain analyze select * from data where vlozeno > '2018-06-01';
┌──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ QUERY PLAN
│
╞══════════════════════════════════════════════════════════════════════════════════════════════════════════════════════╡
│ Append (cost=0.00..3519.83 rows=20001 width=9) (actual
time=0.042..27.750 rows=19428 loops=1) │
│ -> Seq Scan on data_other (cost=0.00..3419.83 rows=20001
width=9) (actual time=0.040..25.895 rows=19428 loops=1) │
│ Filter: (vlozeno > '2018-06-01'::date)
│
│ Rows Removed by Filter: 171518
│
│ Planning Time: 0.766 ms
│
│ Execution Time: 28.718 ms
│
└──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
(6 rows)

postgres=# explain analyze select * from data where vlozeno > current_date;
┌─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ QUERY
PLAN │
╞═════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════════╡
│ Gather (cost=1000.00..17281.36 rows=20080 width=9) (actual
time=0.749..95.389 rows=19428 loops=1)
│
│ Workers Planned: 2
│
│ Workers Launched: 2
│
│ -> Parallel Append (cost=0.00..14273.36 rows=8367 width=9)
(actual time=59.141..89.458 rows=6476 loops=3) │
│ -> Parallel Seq Scan on data_2016 (cost=0.00..5768.69
rows=24 width=9) (actual time=34.847..34.847 rows=0 loops=3) │
│ Filter: (vlozeno > CURRENT_DATE)
│
│ Rows Removed by Filter: 135119
│
│ -> Parallel Seq Scan on data_2017 (cost=0.00..5745.02
rows=23 width=9) (actual time=53.269..53.269 rows=0 loops=2) │
│ Filter: (vlozeno > CURRENT_DATE)
│
│ Rows Removed by Filter: 201848
│
│ -> Parallel Seq Scan on data_other (cost=0.00..2717.82
rows=11765 width=9) (actual time=0.044..55.502 rows=19428 loops=1) │
│ Filter: (vlozeno > CURRENT_DATE)
│
│ Rows Removed by Filter: 171518
│
│ Planning Time: 0.677 ms
│
│ Execution Time: 98.349 ms
│
└─────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
(15 rows)

but

postgres=# explain analyze select * from data where vlozeno > (select
current_date);
┌──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┐
│ QUERY
PLAN │
╞══════════════════════════════════════════════════════════════════════════════════════════════════════════════════════╡
│ Append (cost=0.01..19574.68 rows=333333 width=9) (actual
time=0.095..31.945 rows=19428 loops=1) │
│ InitPlan 1 (returns
$0)
│
│ -> Result (cost=0.00..0.01 rows=1 width=4) (actual
time=0.010..0.010 rows=1 loops=1) │
│ -> Seq Scan on data_2016 (cost=0.00..7258.98 rows=135119 width=9)
(never executed) │
│ Filter: (vlozeno >
$0)
│
│ -> Seq Scan on data_2017 (cost=0.00..7229.20 rows=134565 width=9)
(never executed) │
│ Filter: (vlozeno >
$0)
│
│ -> Seq Scan on data_other (cost=0.00..3419.83 rows=63649 width=9)
(actual time=0.069..29.856 rows=19428 loops=1) │
│ Filter: (vlozeno >
$0)
│
│ Rows Removed by Filter:
171518
│
│ Planning Time: 0.418
ms
│
│ Execution Time: 33.019
ms
│
└──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────┘
(12 rows)

Partition pruning is working now.

Is it expected? Tested on fresh master.

The commit message
https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=499be013de65242235ebdde06adb08db887f0ea5
says so append should be supported.

Regards

Pavel