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Slightly refactor varstr_sortsupport() to improve readability.

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Author: Andreas Karlsson
Discussion: https://postgr.es/m/69c2a864-846f-4309-bd5a-aaa1c34f9a11@proxel.se
This commit is contained in:
Jeff Davis 2024-08-20 14:29:34 -07:00
parent 15c1abd977
commit a95ff1fe2e
1 changed files with 18 additions and 18 deletions
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36
src/backend/utils/adt/varlena.c
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@ -1917,25 +1917,25 @@ varstr_sortsupport(SortSupport ssup, Oid typid, Oid collid)
}
else
ssup->comparator = varlenafastcmp_locale;
}
/*
* Unfortunately, it seems that abbreviation for non-C collations is
* broken on many common platforms; see pg_strxfrm_enabled().
*
* Even apart from the risk of broken locales, it's possible that there
* are platforms where the use of abbreviated keys should be disabled at
* compile time. Having only 4 byte datums could make worst-case
* performance drastically more likely, for example. Moreover, macOS's
* strxfrm() implementation is known to not effectively concentrate a
* significant amount of entropy from the original string in earlier
* transformed blobs. It's possible that other supported platforms are
* similarly encumbered. So, if we ever get past disabling this
* categorically, we may still want or need to disable it for particular
* platforms.
*/
if (!collate_c && !pg_strxfrm_enabled(locale))
abbreviate = false;
/*
* Unfortunately, it seems that abbreviation for non-C collations is
* broken on many common platforms; see pg_strxfrm_enabled().
*
* Even apart from the risk of broken locales, it's possible that there
* are platforms where the use of abbreviated keys should be disabled at
* compile time. Having only 4 byte datums could make worst-case
* performance drastically more likely, for example. Moreover, macOS's
* strxfrm() implementation is known to not effectively concentrate a
* significant amount of entropy from the original string in earlier
* transformed blobs. It's possible that other supported platforms are
* similarly encumbered. So, if we ever get past disabling this
* categorically, we may still want or need to disable it for particular
* platforms.
*/
if (!pg_strxfrm_enabled(locale))
abbreviate = false;
}
/*
* If we're using abbreviated keys, or if we're using a locale-aware