From: Andrew Gierth <andrew@tao11.riddles.org.uk>
To: tank.zhang <6220104@qq.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Postgresql Sort cost Poor performance?
Date: Mon, 01 Apr 2019 11:20:48 +0100
Message-ID: <87d0m6uj5u.fsf@news-spur.riddles.org.uk> (raw)
In-Reply-To: <1554111914781-0.post@n3.nabble.com>
References: <1554111914781-0.post@n3.nabble.com>
>>>>> "tank" == tank zhang <6220104@qq.com> writes:
tank> smtoc | character varying(50) | | |
tank> Sort Key: smtoc
What is the output of SHOW lc_collate;
One of the most common reasons for slow sorting is that you're sorting a
text/varchar field in a locale other than C. The slowdown for using
other locales varies according to the data, the locale, and the
operating system, but 8-20x slowdowns are very common, 50-100x slowdowns
are not unusual, and there have been reports of even worse cases with
unusual script combinations.
--
Andrew (irc:RhodiumToad)
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To: pgsql-performance@postgresql.org
Cc: andrew@tao11.riddles.org.uk, 6220104@qq.com
Subject: Re: Postgresql Sort cost Poor performance?
In-Reply-To: <87d0m6uj5u.fsf@news-spur.riddles.org.uk>
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