From: | "Dean Gibson (DB Administrator)" <postgresql(at)mailpen(dot)com> |
---|---|
To: | "pgsql-performance(at)lists(dot)postgresql(dot)org" <pgsql-performance(at)lists(dot)postgresql(dot)org> |
Subject: | Re: AWS forcing PG upgrade from v9.6 a disaster |
Date: | 2021-05-31 04:23:43 |
Message-ID: | 5463af86-9007-1094-78bf-18e54c60edaf@mailpen.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers pgsql-performance |
On 2021-05-30 20:41, Christophe Pettus wrote:
> On May 30, 2021, at 20:07, Dean Gibson (DB Administrator)
> <postgresql(at)mailpen(dot)com> wrote:
>> The first two JOINs are not the problem, & are in fact retained in my solution. The problem is the third JOIN, where "fips_county" from "County" is actually matched with the corresponding field from the "zip_code" VIEW. Works fine, if you don't mind the performance impact in v10 & above. It has now been rewritten, to be a sub-query for an output field. Voila ! Back to sub-second query times.
> If, rather than a subquery, you explicitly called out the join criteria with ON, did it have the same performance benefit?
I thought that having a "USING" clause, was semantically equivalent to
an "ON" clause with the equalities explicitly stated. So no, I didn't
try that.
The matching that occurred is *exactly *what I wanted. I just didn't
want the performance impact.
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2021-05-31 04:44:27 | Re: AWS forcing PG upgrade from v9.6 a disaster |
Previous Message | Tom Lane | 2021-05-31 04:05:12 | Re: Multiple hosts in connection string failed to failover in non-hot standby mode |
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2021-05-31 04:44:27 | Re: AWS forcing PG upgrade from v9.6 a disaster |
Previous Message | Christophe Pettus | 2021-05-31 03:41:28 | Re: AWS forcing PG upgrade from v9.6 a disaster |