Re: Accounting for between table correlation

On Fri, Jan 15, 2021 at 8:44 AM Atul Kumar <akumar14871(at)gmail(dot)com> wrote:

> Hi Ron,
>
> I have a simple mindset that If I don’t know about something about
> anyone’s query I don’t respond.
>
> Please start learning to not to interrupt or raising useless questions/
> phrases on someone’s query bcz it makes you judgemental.
>
> So please take an advice to not to interrupt if you can’t help. It would
> be helpful for all of us.
>

This advice isn't all that helpful as it presumes that the author of the
response actually understands that what they are writing is not helpful.
That isn't always obvious to the writer, and if it was it probably would
not have been written. Instead, if you find a piece of advice to be
unhelpful, and feel the need to say so, be explicit about why you believe
the response was not helpful.

As to the question at hand - it is correct that "analyze" being run or not
doesn't really matter here - PostgreSQL doesn't have cross-table statistics
that can be updated. That is about the most one can glean from the limited
information the OP provided. Now, if you can place the columns on the same
table, say in a materialized view, and then use the somewhat recent
multi-column statistics feature, there is probably room for improvement.

Otherwise, the question is basically an open-ended one and maybe someone
responds with some rules-of-thumb, or maybe they don't.

David J.