Re: [HACKERS] path toward faster partition pruning - Mailing list pgsql-hackers

From Jesper Pedersen
Subject Re: [HACKERS] path toward faster partition pruning
Date
Msg-id 8d438921-9872-f978-4a5a-650c1ca65790@redhat.com
Whole thread Raw
In response to Re: [HACKERS] path toward faster partition pruning  (Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>)
Responses Re: [HACKERS] path toward faster partition pruning
List pgsql-hackers
Hi Amit,

On 03/27/2018 06:42 AM, Amit Langote wrote:
> I have managed to make the recursion go away in the attached updated
> version.  I guess that's the result of employing the idea of a "output
> register" for individual pruning steps as mentioned in Robert's email
> upthread where he detailed the "pruning steps" approach [1].
> 
> With the new patch, pruning steps for arguments of, say, an OR clause are
> not performed recursively.  Instead, each pruning step is performed
> independently and its output is stored in a slot dedicated to it.  Combine
> steps are always executed after all of the steps corresponding to its
> arguments have been executed.  That's ensured by the way steps are allocated.
> 

Running v41 with "partition_prune" under valgrind gives the attached report.

Best regards,
  Jesper

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