Re: Crash in BRIN minmax-multi indexes

On 4/1/21 3:09 PM, Zhihong Yu wrote:
> Hi,
> Can you try this patch ?
> 
> Thanks
> 
> diff --git a/src/backend/access/brin/brin_minmax_multi.c
> b/src/backend/access/brin/brin_minmax_multi.c
> index 70109960e8..25d6d2e274 100644
> --- a/src/backend/access/brin/brin_minmax_multi.c
> +++ b/src/backend/access/brin/brin_minmax_multi.c
> @@ -2161,7 +2161,7 @@ brin_minmax_multi_distance_interval(PG_FUNCTION_ARGS)
>      delta = 24L * 3600L * delta;
> 
>      /* and add the time part */
> -    delta += result->time / (float8) 1000000.0;
> +    delta += (result->time + result->zone * USECS_PER_SEC) / (float8)
> 1000000.0;
> 

That won't work, because Interval does not have a "zone" field, so this
won't even compile.

The problem is that interval comparisons convert the value using 30 days
per month (see interval_cmp_value), but the formula in this function
uses 31. So either we can tweak that (seems to fix it for me), or maybe
just switch to interval_cmp_value directly.

regards

-- 
Tomas Vondra
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