Re: PoC/WIP: Extended statistics on expressions - Mailing list pgsql-hackers

From Dean Rasheed
Subject Re: PoC/WIP: Extended statistics on expressions
Date
Msg-id CAEZATCVjxvLsn_kXKC+dgVo7OGBBNROGq4Ok5N1QAoMN7Bg8gQ@mail.gmail.com
Whole thread Raw
In response to Re: PoC/WIP: Extended statistics on expressions  (Justin Pryzby <pryzby@telsasoft.com>)
Responses Re: PoC/WIP: Extended statistics on expressions  (Tomas Vondra <tomas.vondra@enterprisedb.com>)
List pgsql-hackers
On Fri, 22 Jan 2021 at 04:46, Justin Pryzby <pryzby@telsasoft.com> wrote:
>
> I think you'll maybe have to do something better - this seems a bit too weird:
>
> | postgres=# CREATE STATISTICS s2 ON (i+1) ,i FROM t;
> | postgres=# \d t
> | ...
> |     "public"."s2" (ndistinct, dependencies, mcv) ON i FROM t
>

I guess that's not surprising, given that old psql knows nothing about
expressions in stats.

In general, I think connecting old versions of psql to newer servers
is not supported. You're lucky if \d works at all. So it shouldn't be
this patch's responsibility to make that output nicer.

Regards,
Dean



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