Re: Columns correlation and adaptive query optimization - Mailing list pgsql-hackers

From Konstantin Knizhnik
Subject Re: Columns correlation and adaptive query optimization
Date
Msg-id 5caf8a0a-2849-2c22-2b66-78e0c57ce834@postgrespro.ru
Whole thread Raw
In response to Re: Columns correlation and adaptive query optimization  (Yugo NAGATA <nagata@sraoss.co.jp>)
Responses Re: Columns correlation and adaptive query optimization
Re: Columns correlation and adaptive query optimization
Re: Columns correlation and adaptive query optimization
List pgsql-hackers

On 19.03.2021 12:17, Yugo NAGATA wrote:
> On Wed, 10 Mar 2021 03:00:25 +0100
> Tomas Vondra <tomas.vondra@enterprisedb.com> wrote:
>
>> What is being proposed here - an extension suggesting which statistics
>> to create (and possibly creating them automatically) is certainly
>> useful, but I'm not sure I'd call it "adaptive query optimization". I
>> think "adaptive" means the extension directly modifies the estimates
>> based on past executions. So I propose calling it maybe "statistics
>> advisor" or something like that.
> I am also agree with the idea to implement this feature as a new
> extension for statistics advisor.
>
>> BTW Why is "qual" in
>>
>>    static void
>>    AddMultiColumnStatisticsForQual(void* qual, ExplainState *es)
>>
>> declared as "void *"? Shouldn't that be "List *"?
> When I tested this extension using TPC-H queries, it raised segmentation
> fault in this function. I think the cause would be around this argument.
>
> Regards,
> Yugo Nagata
>
Attached please find new version of the patch with 
AddMultiColumnStatisticsForQual parameter type fix and one more fix 
related with handling synthetic attributes.
I can not reproduce the crash on TPC-H queries, so if the problem 
persists, can you please send me stack trace and may be some other 
information helping to understand the reason of SIGSEGV?

Thanks in advance,
Konstantin


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