From: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
To: Andreas Karlsson <andreas@proxel.se>
To: pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: insensitive collations
Date: Thu, 10 Jan 2019 08:44:35 +0100
Message-ID: <3e5bfc15-61e4-ecdc-81b2-55d036717a10@2ndquadrant.com> (raw)
In-Reply-To: <9fd63f66-fb85-9bb9-2499-28dac918161a@proxel.se>
References: <1ccc668f-4cbc-0bef-af67-450b47cdfee7@2ndquadrant.com>
<cdd0ed2e-1d98-6fc4-07f1-23f19f53b201@2ndquadrant.com>
<9fd63f66-fb85-9bb9-2499-28dac918161a@proxel.se>
On 09/01/2019 19:49, Andreas Karlsson wrote:
> On 12/28/18 9:55 AM, Peter Eisentraut wrote:
>> Here is an updated patch.
>>
>> I have updated the naming to "deterministic", as discussed.
>
> Maybe this is orthogonal and best handled elsewhere but have you when
> working with string equality given unicode normalization forms[1] any
> thought?
Nondeterministic collations do address this by allowing canonically
equivalent code point sequences to compare as equal. You still need a
collation implementation that actually does compare them as equal; ICU
does this, glibc does not AFAICT.
> Would there be any point in adding unicode normalization support into
> the collation system or is this best handle for example with a function
> run on INSERT or with something else entirely?
I think there might be value in a feature that normalizes strings as
they enter the database, as a component of the encoding conversion
infrastructure. But that would be a separate feature.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
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To: pgsql-hackers@postgresql.org
Cc: peter.eisentraut@2ndquadrant.com, andreas@proxel.se
Subject: Re: insensitive collations
In-Reply-To: <3e5bfc15-61e4-ecdc-81b2-55d036717a10@2ndquadrant.com>
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