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Mysql分區(qū)表對于唯一約束的局限性
Mysql分區(qū)表相信大家都有一些了解，下面就為您介紹Mysql分區(qū)表對于唯一約束的局限性，如果您對此方面感興趣的話，不妨一看。
Mysql分區(qū)表關(guān)于Partitioning Keys, Primary Keys, and Unique Keys的限制
在5.1中Mysql分區(qū)表對唯一約束有明確的規(guī)定，每一個唯一約束必須包含在分區(qū)表的分區(qū)鍵（也包括主鍵約束）。
這句話也許不好理解，我們做幾個實(shí)驗(yàn)：
- CREATE TABLE t1
- ( id INT NOT NULL,
- uid INT NOT NULL,
- PRIMARY KEY (id)
- )
- PARTITION BY RANGE (id)
- (PARTITION p0 VALUES LESS THAN(5) ENGINE = INNODB,
- PARTITION p1 VALUES LESS THAN(10) ENGINE = INNODB);
- CREATE TABLE t1
- ( id INT NOT NULL,
- uid INT NOT NULL,
- PRIMARY KEY (id)
- )
- PARTITION BY RANGE (id)
- (PARTITION p0 VALUES LESS THAN(5) ENGINE = MyISAM DATA DIRECTORY='/tmp' INDEX DIRECTORY='/tmp',
- PARTITION p1 VALUES LESS THAN(10) ENGINE = MyISAM DATA DIRECTORY='/tmp' INDEX DIRECTORY='/tmp');
- mysql> CREATE TABLE t1
- -> ( id INT NOT NULL,
- -> uid INT NOT NULL,
- -> PRIMARY KEY (id),
- -> UNIQUE KEY (uid)
- -> )
- -> PARTITION BY RANGE (id)
- -> (PARTITION p0 VALUES LESS THAN(5),
- -> PARTITION p1 VALUES LESS THAN(10)
- -> );ERROR 1503 (HY000): A UNIQUE INDEX must include all columns in the table's partitioning function
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網(wǎng)頁標(biāo)題：Mysql分區(qū)表對于唯一約束的局限性
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