Postgres Pro
Downloads
Home   >   mailing lists

Re: need explanation about an explain plan - Mailing list pgsql-general

From Marc Millas
Subject Re: need explanation about an explain plan
Date
Msg-id CADX_1aYVmbrbJi+62b06XWuLzn6CJs6P0K=wEDinJjcGvkuC+g@mail.gmail.com
Whole thread Raw
In response to need explanation about an explain plan  (Marc Millas <marc.millas@mokadb.com>)
Responses Re: need explanation about an explain plan  (Laurenz Albe <laurenz.albe@cybertec.at>)
List pgsql-general
Tree view
Sorry, gmail sent uncompleted message
  
Hi,

Postgres 14.2  (for one more month)
The explain plan and request is here:

The big table (10 billions raws) is split in around 130 partitions, one by month.
the ladate column is the partition key, and it does have 1 value for each partition.
there is an index on the numfic column. the distribution of values for that column may differ before and after 2019 january.

The request is executed in a loop for all ten years of data, year 1,2,3, then year2,3,4 etc
that request is also executed for columns other than cod, one column at a time (there are 107 columns...)

I dont understand why the planner use a filter on the date, as its already within the partition structure.

Thanks,

Marc MILLAS




On Wed, Jun 28, 2023 at 5:22 PM Marc Millas <marc.millas@mokadb.com> wrote:
Hi,

Postgres 14.2  (for one more month)
The explain plan and request is here:

The big table is split in around 130 partitions, one by month.
the ladate column is the partition key, and it does have 1 value for each partition.
there is a




Marc MILLAS
Senior Architect
+33607850334

pgsql-general by date:

Previous
From: Marc Millas
Date:
Subject: need explanation about an explain plan
Next
From: Laurenz Albe
Date:
Subject: Re: need explanation about an explain plan