RE: speeding up planning with partitions - Mailing list pgsql-hackers

From Imai, Yoshikazu
Subject RE: speeding up planning with partitions
Date
Msg-id 0F97FA9ABBDBE54F91744A9B37151A51259E1A@g01jpexmbkw24
Whole thread Raw
In response to RE: speeding up planning with partitions  ("Tsunakawa, Takayuki" <tsunakawa.takay@jp.fujitsu.com>)
Responses Re: speeding up planning with partitions
List pgsql-hackers
Tsunakawa-san

Thanks for giving the information.
I didn't use it yet, but I just used perf to clarify the difference of before and after the creation of the generic
plan,and I noticed that usage of hash_seq_search() is increased about 3% in EXECUTE queries after the creation of the
genericplan.
 

What I understand so far is about 10,000 while loops at total (4098+4098+some extra) is needed in hash_seq_search() in
EXECUTEquery after the creation of the generic plan.
 
10,000 while loops takes about 10 microsec (of course, we can't estimate correct time), and the difference of the
latencybetween 5th and 7th EXECUTE is about 8 microsec, I currently think this causes the difference.
 

I don't know this problem relates to Amit-san's patch, but I'll continue to investigate it.

Yoshikazu Imai


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