From: | Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)com> |
---|---|
To: | Peter Geoghegan <pg(at)bowt(dot)ie> |
Cc: | Daniel Verite <daniel(at)manitou-mail(dot)org>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: insensitive collations |
Date: | 2019-02-21 17:11:27 |
Message-ID: | 3548cbab-2c29-be93-0c9c-ec24136626ae@2ndquadrant.com |
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Lists: | pgsql-hackers |
On 2019-02-21 09:36, Peter Eisentraut wrote:
>> * Why have you disable this optimization?:
>>
>>> /* Fast pre-check for equality, as discussed in varstr_cmp() */
>>> - if (len1 == len2 && memcmp(a1p, a2p, len1) == 0)
>>> + if ((!sss->locale || sss->locale->deterministic) &&
>>> + len1 == len2 && memcmp(a1p, a2p, len1) == 0)
>> I don't see why this is necessary. A non-deterministic collation
>> cannot indicate that bitwise identical strings are non-equal.
> Right, I went too far there.
>
>> * Perhaps you should add a "Tip" referencing the feature to the
>> contrib/citext documentation.
> Good idea.
Here is another patch that fixes these two points.
I have also worked on the tests hoping to appease the cfbot.
Older ICU versions (<54) don't support all the locale customization
options, so many of my new tests in collate.icu.utf8.sql will fail on
older systems. What should we do about that? Have another extra test file?
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Attachment | Content-Type | Size |
---|---|---|
v7-0001-Collations-with-nondeterministic-comparison.patch | text/plain | 152.9 KB |
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