| From: | Merlin Moncure <mmoncure(at)gmail(dot)com> |
|---|---|
| To: | Bob Jolliffe <bobjolliffe(at)gmail(dot)com> |
| Cc: | Peter Geoghegan <pg(at)bowt(dot)ie>, pgsql-performance(at)lists(dot)postgresql(dot)org |
| Subject: | Re: How can sort performance be so different |
| Date: | 2019-02-20 21:35:42 |
| Message-ID: | CAHyXU0wAGdhSjR8v+4=gX0bJpuXUYRpLExY2Xe-bHiTrDFEvtA@mail.gmail.com |
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| Lists: | pgsql-performance |
On Mon, Feb 18, 2019 at 9:49 AM Bob Jolliffe <bobjolliffe(at)gmail(dot)com> wrote:
>
> Sorry Merlin for not replying earlier. The difference is indeed hard
> to understand but it is certainly there. We altered the collation to
> use on the name field in that table and the problem has gone. Having
> having solved the immediate problem we haven't investigated much
> further yet.
>
> Not sure what exactly you mean by "other conversions"?
I hand tested similar query for other (generally western) collations.
Did not observe anything nearly so bad. What I'm hoping is that this
is some kind of weird performance issue specific to your installation;
in the worst (unfortunately likely) case we are looking at something
specific to your specific sort collation :(.
merlin
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