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sql: fix config name in collation doc #2946

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TomShawn merged 2 commits into from
May 8, 2020
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sql: fix config name in collation doc #2946

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sql: fix config name in collation doc
TomShawn May 1, 2020
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Merge branch 'master' into change-config-name
wjhuang2016 May 8, 2020
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4 changes: 2 additions & 2 deletions reference/sql/characterset-and-collation.md
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Expand Up @@ -280,7 +280,7 @@ SET collation_connection = @@collation_database;

## 排序规则支持

排序规则的语法支持和语义支持受到配置项 [`new_collation_enable`](/reference/configuration/tidb-server/configuration-file.md#new_collations_enabled_on_first_bootstrap) 的影响。这里语法支持和语义支持有所区别。语法支持是指 TiDB 能够解析和设置排序规则；而语义支持是指 TiDB 能够在比较字符串时正确地使用排序规则。
排序规则的语法支持和语义支持受到配置项 [`new_collations_enabled_on_first_bootstrap`](/reference/configuration/tidb-server/configuration-file.md#new_collations_enabled_on_first_bootstrap) 的影响。这里语法支持和语义支持有所区别。语法支持是指 TiDB 能够解析和设置排序规则；而语义支持是指 TiDB 能够在比较字符串时正确地使用排序规则。

在 4.0 版本之前，TiDB 只提供了旧的排序规则框架，能够在语法上支持的绝大部分 MySQL 排序规则，但语义上所有的排序规则都当成二进制排序规则。

Expand All @@ -305,7 +305,7 @@ Query OK, 1 row affected # MySQL 中，由于补齐空格比较，报错 Duplica

### 新框架下的排序规则支持

TiDB 4.0 新增了完整的排序规则支持框架，从语义上支持了排序规则，并新增了配置开关 `new_collation_enabled_on_first_boostrap`，在集群初次初始化时决定是否启用新排序规则框架。在该配置开关打开之后初始化集群，可以通过 `mysql`.`tidb` 表中的 `new_collation_enabled` 变量确认是否启用新排序规则框架：
TiDB 4.0 新增了完整的排序规则支持框架，从语义上支持了排序规则，并新增了配置开关 `new_collations_enabled_on_first_bootstrap`，在集群初次初始化时决定是否启用新排序规则框架。在该配置开关打开之后初始化集群，可以通过 `mysql`.`tidb` 表中的 `new_collation_enabled` 变量确认是否启用新排序规则框架：

{{< copyable "sql" >}}

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