character-set | 易学教程

Does using ASCII/Latin Charset speed up the database?

阅读更多关于 Does using ASCII/Latin Charset speed up the database?

问题 It would seem that using the ASCII charset for most fields and then specify utf8 only for the fields that need it would reduce the amount of I/O the database must perform by 100%. Anyone know if this is true? Update: The above was not really my question. I should have said: use Latin for the default character set and then only specify utf8mb4 only for the fields that need it. The thinking being that: using 1 byte vs 2 bytes should improve I/O by 100%. Sorry for the confusion. 回答1: @RickJames

Reduce MySQL queries to one query to speed up

阅读更多关于 Reduce MySQL queries to one query to speed up

问题 In general_log file i have queries: 160806 9:53:26 11 Connect dbname@localhost on 11 Query SET NAMES utf8 11 Query SET character_set_client="utf8" 11 Query SET character_set_connection="utf8" 11 Query SET character_set_database="utf8" 11 Query SET character_set_results="utf8" 11 Query SET character_set_server="utf8" 11 Query SET character_set_system="utf8" 11 Init DB dbname Is that possible to make 1 query instead of 7 queries? Will it speed up significantly? 回答1: See if I am currently

vb.net character set

阅读更多关于 vb.net character set

问题 According to MSDN vb.net uses this extended character set. In my experience it actually uses this: What am I missing? Why does it say it uses the one and uses the other? Am I doing something wrong? Is there some sort of conversion tool to the original character set? 回答1: This behaviour is defined in the documentation of the Chr command: The returned value depends on the code page for the current thread, which is contained in the ANSICodePage property of the TextInfo class in the System

error_log flooded by “charset not supported, assuming utf-8” messages

阅读更多关于 error_log flooded by “charset not supported, assuming utf-8” messages

问题 The issue: Wordpress blog's error log is flooded by "charset not supported, assuming utf-8" messages; grows 0 bytes to 450 Mb in 24 hrs (~28k page views, if stats are correct). Details: I have a Wordppress-powered blog hosted on shared hosting account. It's been running for years, and this was never an issue until not too long ago, but I can't pinpoint the exact time frame when this started to happen. A few months ago I started to exceed my allowed resources (memory mostly), so they moved me

Does using ASCII/Latin Charset speed up the database?

阅读更多关于 Does using ASCII/Latin Charset speed up the database?

It would seem that using the ASCII charset for most fields and then specify utf8 only for the fields that need it would reduce the amount of I/O the database must perform by 100%. Anyone know if this is true? Update: The above was not really my question. I should have said: use Latin for the default character set and then only specify utf8mb4 only for the fields that need it. The thinking being that: using 1 byte vs 2 bytes should improve I/O by 100%. Sorry for the confusion. @RickJames is right, you should not worry about saving space by choosing ASCII or utf8 over utf8mb4. utf8 and utf8mb4

About the “Character set” option in Visual Studio

阅读更多关于 About the “Character set” option in Visual Studio

问题 I have an inquiry about the "Character set" option in Visual Studio. The Character Set options are: Not Set Use Unicode Character Set Use Multi-Byte Character Set I want to know what the difference between three options in Character Set? Also if I choose something of them, will affect the support for languages other than English (like RTL languages)? 回答1: It is a compatibility setting, intended for legacy code that was written for old versions of Windows that were not Unicode enabled.

What does character set and collation mean exactly?

阅读更多关于 What does character set and collation mean exactly?

问题 I can read the MySQL documentation and it\'s pretty clear. But, how does one decide which character set to use? On what data does collation have an effect? I\'m asking for an explanation of the two and how to choose them. 回答1: From MySQL docs: A character set is a set of symbols and encodings. A collation is a set of rules for comparing characters in a character set. Let's make the distinction clear with an example of an imaginary character set. Suppose that we have an alphabet with four

Best way to convert text files between character sets?

阅读更多关于 Best way to convert text files between character sets?

问题 What is the fastest, easiest tool or method to convert text files between character sets? Specifically, I need to convert from UTF-8 to ISO-8859-15 and vice versa. Everything goes: one-liners in your favorite scripting language, command-line tools or other utilities for OS, web sites, etc. Best solutions so far: On Linux/UNIX/OS X/cygwin: Gnu iconv suggested by Troels Arvin is best used as a filter . It seems to be universally available. Example: $ iconv -f UTF-8 -t ISO-8859-15 in.txt > out

What's the difference between utf8_general_ci and utf8_unicode_ci

阅读更多关于 What's the difference between utf8_general_ci and utf8_unicode_ci

问题 Between utf8_general_ci and utf8_unicode_ci , are there any differences in terms of performance? 回答1: These two collations are both for the UTF-8 character encoding. The differences are in how text is sorted and compared. Note: You should use utf8mb4 rather than utf8 . They both refer to the UTF-8 encoding, but the older utf8 had a MySQL-specific limitation preventing use of characters numbered above 0xFFFD. Note: Newer versions of MySQL have updated Unicode sorting rules, available under