Amit-san,

I have done code review of v31 patches from 0004 to 0008.

0004:
* s/childern/children

0005:
* This seems reasonable for not using a lot of memory in specific case, 
although it needs special looking of planner experts.

0006:
* The codes initializing/setting RelOptInfo's part_rels looks like a bit 
complicated, but I didn't come up with any good design so far.

0007:
* This changes some processes using "for loop" to using 
"while(bms_next_member())" which speeds up processing when we scan few 
partitions in one statement, but when we scan a lot of partitions in one 
statement, its performance will likely degraded. I measured the performance of 
both cases.
I executed select statement to the table which has 4096 partitions.

[scanning 1 partition]
Without 0007 : 3,450 TPS
With 0007    : 3,723 TPS

[scanning 4096 partitions]
Without 0007 : 10.8 TPS
With 0007    : 10.5 TPS

In the above result, performance degrades 3% in case of scanning 4096 
partitions compared before and after applying 0007 patch. I think when scanning 
a lot of tables, executor time would be also longer, so the increasement of 
planner time would be relatively smaller than it. So we might not have to care 
this performance degradation.

0008:
This seems ok.


--
Yoshikazu Imai

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