Amit-san, > From: Amit Langote [mailto:langote_amit...@lab.ntt.co.jp] > Sent: Wednesday, February 27, 2019 11:22 AM > > Hosoya-san, > > On 2019/02/22 17:14, Yuzuko Hosoya wrote: > > Hi, > > > > I found the bug of default partition pruning when executing a range query. > > > > ----- > > postgres=# create table test1(id int, val text) partition by range > > (id); postgres=# create table test1_1 partition of test1 for values > > from (0) to (100); postgres=# create table test1_2 partition of test1 > > for values from (150) to (200); postgres=# create table test1_def > > partition of test1 default; > > > > postgres=# explain select * from test1 where id > 0 and id < 30; > > QUERY PLAN > > ---------------------------------------------------------------- > > Append (cost=0.00..11.83 rows=59 width=11) > > -> Seq Scan on test1_1 (cost=0.00..5.00 rows=58 width=11) > > Filter: ((id > 0) AND (id < 30)) > > -> Seq Scan on test1_def (cost=0.00..6.53 rows=1 width=12) > > Filter: ((id > 0) AND (id < 30)) > > (5 rows) > > > > There is no need to scan the default partition, but it's scanned. > > ----- > > > > In the current implement, whether the default partition is scanned or > > not is determined according to each condition of given WHERE clause at > > get_matching_range_bounds(). In this example, scan_default is set > > true according to id > 0 because id >= 200 matches the default > > partition. Similarly, according to id < 30, scan_default is set true. > > Then, these results are combined according to AND/OR at > > perform_pruning_combine_step(). > > In this case, final result's scan_default is set true. > > > > The modifications I made are as follows: > > - get_matching_range_bounds() determines only offsets of range bounds > > according to each condition > > - These results are combined at perform_pruning_combine_step() > > - Whether the default partition is scanned or not is determined at > > get_matching_partitions() > > > > Attached the patch. Any feedback is greatly appreciated. > > Thank you for reporting. Can you please add this to March CF in Bugs > category so as not to lose track > of this? > > I will try to send review comments soon. > Thank you for your reply. I added this to March CF.
Regards, Yuzuko Hosoya NTT Open Source Software Center
