Re: Declarative partitioning

On 2016-04-15 04:35, Amit Langote wrote:

A quick test with:

> 0001-Add-syntax-to-specify-partition-key-v3.patch
> 0002-Infrastructure-for-creation-of-partitioned-tables-v3.patch
> 0003-Add-syntax-to-create-partitions-v3.patch
> 0004-Infrastructure-for-partition-metadata-storage-and-ma-v3.patch
> 0005-Introduce-tuple-routing-for-partitioned-tables-v3.patch

patches apply, build and make check ok.

There is somwthing wrong with indexes on child tables (and only with 
higher rowcounts).

Surely the below code should give 6 rows; it actually does return 6 rows 
without the indexes.
With indexes it returns 0 rows.

(but when doing the same test with low rowcounts, things are OK.)


thanks,

Erik Rijkers


(Linux Centos 6.6)


---------------------------------------
create table inh(a int, b int) partition by range ((a+b));
create table inh_1 partition of inh for values start (     0) end (  
10000);
create table inh_2 partition of inh for values start ( 10000) end (  
20000);
create table inh_3 partition of inh for values start ( 20000) end ( 
100000);

create index inh_1_a_idx on inh_1 (a);
create index inh_2_a_idx on inh_2 (a);
create index inh_3_a_idx on inh_3 (a);

insert into inh select i, i as j from generate_series(1, 10000) as f(i);

analyze inh_1;
analyze inh_2;
analyze inh_3;
          select 'inh'  , count(*)  from inh
union all select 'inh_1', count(*)  from inh_1
union all select 'inh_2', count(*)  from inh_2
union all select 'inh_3', count(*)  from inh_3
;

explain analyze  select * from inh where a between 10110 and 10115;
---------------------------------------



# output :

create table inh(a int, b int) partition by range ((a+b));
create table inh_1 partition of inh for values start (     0) end (  
10000);  create index inh_1_a_idx on inh_1 (a);
create table inh_2 partition of inh for values start ( 10000) end (  
20000);  create index inh_2_a_idx on inh_2 (a);
create table inh_3 partition of inh for values start ( 20000) end ( 
100000);  create index inh_3_a_idx on inh_3 (a);
insert into inh select i, i as j from generate_series(1, 10000) as f(i);
analyze inh_1;
analyze inh_2;
analyze inh_3;          select 'inh'  , count(*)  from inh
union all select 'inh_1', count(*)  from inh_1
union all select 'inh_2', count(*)  from inh_2
union all select 'inh_3', count(*)  from inh_3
; ?column? | count
----------+------- inh      | 10000 inh_1    |  4999 inh_2    |  5000 inh_3    |     1
(4 rows)

explain analyze  select * from inh where a between 10110 and 10115;
 QUERY PLAN
 

-------------------------------------------------------------------------------------------------------------------------
Append (cost=0.00..17.37 rows=4 width=8) (actual time=0.023..0.023 
 
rows=0 loops=1)   ->  Seq Scan on inh  (cost=0.00..0.00 rows=1 width=8) (actual 
time=0.004..0.004 rows=0 loops=1)         Filter: ((a >= 10110) AND (a <= 10115))   ->  Index Scan using inh_1_a_idx on
inh_1 (cost=0.16..8.18 rows=1 
 
width=8) (actual time=0.007..0.007 rows=0 loops=1)         Index Cond: ((a >= 10110) AND (a <= 10115))   ->  Index Scan
usinginh_2_a_idx on inh_2  (cost=0.16..8.18 rows=1 
 
width=8) (actual time=0.002..0.002 rows=0 loops=1)         Index Cond: ((a >= 10110) AND (a <= 10115))   ->  Seq Scan
oninh_3  (cost=0.00..1.01 rows=1 width=8) (actual 
 
time=0.008..0.008 rows=0 loops=1)         Filter: ((a >= 10110) AND (a <= 10115))         Rows Removed by Filter: 1
Planningtime: 0.858 ms Execution time: 0.093 ms
 
(12 rows)