Re: Columns correlation and adaptive query optimization

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

-- 
Yugo NAGATA <nagata@sraoss.co.jp>