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Thread: extended statistics n-distinct on multiple columns not used when join two tables

extended statistics n-distinct on multiple columns not used when join two tables

From
"James Pang (chaolpan)"
Date:

Hi,

     When join two table on multiple columns equaljoin, rows estimation always use selectivity = multiplied by distinct multiple individual columns, possible to use  extended n-distinct statistics on multiple columns?

    PG v14.8-1, attached please check test case with details.

 

Thanks,

 

James

      

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Re: extended statistics n-distinct on multiple columns not used when join two tables

From
Pavel Stehule
Date:
Hi

út 13. 6. 2023 v 11:21 odesílatel James Pang (chaolpan) <chaolpan@cisco.com> napsal:

Hi,

     When join two table on multiple columns equaljoin, rows estimation always use selectivity = multiplied by distinct multiple individual columns, possible to use  extended n-distinct statistics on multiple columns?

    PG v14.8-1, attached please check test case with details.


There is not any support for multi tables statistic

Regards

Pavel
 

 

Thanks,

 

James