| From: | David Rowley <david(dot)rowley(at)2ndquadrant(dot)com> |
|---|---|
| To: | Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> |
| Cc: | Ashutosh Bapat <ashutosh(dot)bapat(at)enterprisedb(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Amit Langote <amitlangote09(at)gmail(dot)com>, Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: [HACKERS] path toward faster partition pruning |
| Date: | 2018-04-11 12:04:56 |
| Message-ID: | CAKJS1f-XOAdJjcP8yC3F6dwZ3FJBZDBShjdmyWbcmVVKDaOy2A@mail.gmail.com |
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| Lists: | pgsql-hackers |
On 11 April 2018 at 21:22, Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> wrote:
>> Also just wondering if it's worth adding some verification that we've
>> actually eliminated the correct partitions by backing the tests up
>> with a call to satisfies_hash_partition.
>>
>> I've attached a delta patch that applies to your v2 which does this.
>> Do you think it's worth doing?
>
> We can see check by inspection that individual values are in appropriate
> partitions, which is the point of having the inserts and the select just
> above the actual pruning related tests. So, I'm not sure if adding the
> satisfies_hash_partition against each pruning tests adds much.
Right, that's true.
> Attached revised patch.
Thanks. It looks fine to me, with or without the
satisfies_hash_partition tests. I agree that they're probably
overkill, but I see you've added them now.
--
David Rowley http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
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