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Re: utf8 and utf8mb4 performance difference
Posted by: Rick James ()
Date: September 30, 2016 08:04PM

In 'unicode_520', for example, the two characters "ae" are treated as equal to the single character "æ". Ditto for the 'german2' collation. This is an example of where the the 'general' collation is a little faster -- because it takes less effort.

In most collations "lj" = "lj", but not in 'general'.

A longer list of such differences can be found here: http://mysql.rjweb.org/utf8_collations.html .

There is a third category of collation, 'bin', as in 'utf8_bin' and 'utf8mb4_bin'. These are the fastest, since they blindly compare bits; no case folding; no accent stripping. That is, "A" != "a" != "á", etc.; in all(?) other collations, those are treated as equal. (MySQL 8.0 promises to have some collations that will invalidate this last statement.)

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Subject Views Written By Posted
utf8 and utf8mb4 performance difference 673 hua kai 09/09/2016 07:25AM
Re: utf8 and utf8mb4 performance difference 469 Rick James 09/10/2016 10:48PM
Re: utf8 and utf8mb4 performance difference 363 hua kai 09/12/2016 08:55PM
Re: utf8 and utf8mb4 performance difference 321 Rick James 09/13/2016 04:07PM
Re: utf8 and utf8mb4 performance difference 344 hua kai 09/18/2016 12:20AM
Re: utf8 and utf8mb4 performance difference 309 Peter Brawley 09/18/2016 01:40PM
Re: utf8 and utf8mb4 performance difference 319 hua kai 09/19/2016 02:14AM
Re: utf8 and utf8mb4 performance difference 509 Xing Zhang 09/20/2016 08:38PM
Re: utf8 and utf8mb4 performance difference 334 hua kai 09/25/2016 01:20AM
Re: utf8 and utf8mb4 performance difference 341 Rick James 09/30/2016 08:04PM


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