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

From Imai, Yoshikazu
Subject RE: speeding up planning with partitions
Date
Msg-id 0F97FA9ABBDBE54F91744A9B37151A5125964E@g01jpexmbkw24
Whole thread Raw
In response to Re: speeding up planning with partitions  (Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>)
List pgsql-hackers
Tsunakawa-san

On Thu, Jan 18, 2019 at 5:29 AM, Amit Langote wrote:
> On 2019/01/18 14:12, Tsunakawa, Takayuki wrote:
...
> > Isn't CheckCachedPlan() (and AcquireExecutorLocks() therein) called
> in every EXECUTE after 6th one due to some unknow issue?
> 
> CheckCachedPlan is only called if choose_custom_plan() returns false
> resulting in generic plan being created/reused.  With plan_cache_mode
> = auto, I see it always returns true, because a custom plan containing
> a single partition to scan is way cheaper than the generic plan.
> 
> > Does choose_custom_plan() always return true after 6th EXECUTE?
> 
> Yes.

Yes.
I also checked choose_custom_plan() always returns true excluding 6th EXECUTE
and CheckCachedPlan() is only called at 6th EXECUTE.

Yoshikazu Imai 


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