Re: pgsql: Allow vacuum command to process indexes in parallel. - Mailing list pgsql-committers

From Andres Freund
Subject Re: pgsql: Allow vacuum command to process indexes in parallel.
Date
Msg-id 52A7E56A-4D8D-4701-9332-CAB7A796D2FA@anarazel.de
Whole thread Raw
In response to Re: pgsql: Allow vacuum command to process indexes in parallel.  (Mahendra Singh Thalor <mahi6run@gmail.com>)
List pgsql-committers
Hi,

On March 31, 2020 12:43:47 AM PDT, Mahendra Singh Thalor <mahi6run@gmail.com> wrote:
>On Mon, 30 Mar 2020 at 09:44, Amit Kapila <amit.kapila16@gmail.com>
>wrote:
>>
>> On Mon, Mar 30, 2020 at 4:18 AM Andres Freund <andres@anarazel.de>
>wrote:
>> >
>> > > 2076
>> > > 2077          if ((shared_balance >= VacuumCostLimit) &&
>> > > >>>     CID ...:  Incorrect expression
>(UNINTENDED_INTEGER_DIVISION)
>> > > >>>     Dividing integer expressions "VacuumCostLimit" and
>"nworkers", and then converting the integer quotient to type "double".
>Any remainder, or fractional part of the quotient, is ignored.
>> > > 2078                  (VacuumCostBalanceLocal > 0.5 *
>(VacuumCostLimit / nworkers)))
>> > > 2079          {
>> > > 2080                  /* Compute sleep time based on the local
>cost balance */
>> > > 2081                  msec = VacuumCostDelay *
>VacuumCostBalanceLocal / VacuumCostLimit;
>> > > 2082
>pg_atomic_sub_fetch_u32(VacuumSharedCostBalance,
>VacuumCostBalanceLocal);
>> > > 2083                  VacuumCostBalanceLocal = 0;
>> >
>> > Which seems like a fair enough complaint?
>> >
>>
>> Yeah, how can we set up and test a fix for this?  Where can I see
>these results?
>
>I am able to make coverity setup.  I am verifying fix and will post my
>results in coming days.

That doesn't seem necessary - we should commit a fix. We'll know in a few days for sure. But it's not hard to just
theoreticallylook at the issue in this case? 

Andres
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.



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