MySQL分區表比同等的未分區表工作速度慢

Question

幫助！ 我有MySQL中的表（不分區）與約4個500 000行：

CREATE TABLE stat_accounts_history (
    id bigint(20) NOT NULL AUTO_INCREMENT, 
    accountId bigint(20) DEFAULT NULL, 
    month varchar(255) DEFAULT NULL, 
    purchase decimal(19, 2) DEFAULT NULL, 
    purchaseCard decimal(19, 2) DEFAULT NULL, 
    requiredPurchase decimal(19, 2) DEFAULT NULL, 
    PRIMARY KEY (id), 
    INDEX IDX_stat_accounts_history_accountId (accountId), 
    INDEX IDX_stat_accounts_history_month (month) 
) 
ENGINE = INNODB 
AUTO_INCREMENT = 4707631 
AVG_ROW_LENGTH = 241 
CHARACTER SET utf8 
COLLATE utf8_general_ci; 

我從該表中導出的所有數據，並將其導入到相當於分區表：

CREATE TABLE stat_accounts_history_part (
    accountId bigint(20) NOT NULL, 
    month varchar(255) NOT NULL DEFAULT '', 
    purchase decimal(19, 2) DEFAULT NULL, 
    purchaseCard decimal(19, 2) DEFAULT NULL, 
    requiredPurchase decimal(19, 2) DEFAULT NULL, 
    monthRef bigint(20) NOT NULL DEFAULT 0, 
    PRIMARY KEY (accountId, monthRef), 
    INDEX IDX_stat_accounts_history_part10_monthRef (monthRef), 
    UNIQUE INDEX UK_stat_accounts_history_part1 (id, monthRef) 
) 
ENGINE = INNODB 
AVG_ROW_LENGTH = 242 
CHARACTER SET utf8 
COLLATE utf8_general_ci 
PARTITION BY LIST (monthRef) 
(
PARTITION p2013_01 VALUES IN (9) 
ENGINE = INNODB, 
PARTITION p2013_02 VALUES IN (10) 
ENGINE = INNODB, 
PARTITION p2013_03 VALUES IN (11) 
ENGINE = INNODB, 
PARTITION p2013_04 VALUES IN (12) 
ENGINE = INNODB, 
PARTITION p2013_05 VALUES IN (13) 
ENGINE = INNODB, 
PARTITION p2013_06 VALUES IN (14) 
ENGINE = INNODB, 
PARTITION p2013_07 VALUES IN (15) 
ENGINE = INNODB, 
PARTITION p2013_08 VALUES IN (16) 
ENGINE = INNODB, 
PARTITION p2013_09 VALUES IN (17) 
ENGINE = INNODB 
); 

在我的網站 - 應用（Java + Spring + Hibernate的）我寫的方法來測試查詢該表：

for(int i = 0; i < 100; i++){ 
    long timeIter = System.nanoTime(); 
    dao.createSQLQuery("select count(accountId) from stat_accounts_history_part where monthRef=9 and (purchase+purchaseCard)>=requiredPurchase").list(); 
    System.out.print((long)((System.nanoTime() - timeIter)/1000000) + "\t"); 

    timeIter = System.nanoTime(); 
    dao.createSQLQuery("select count(accountId) from stat_accounts_history_part where monthRef=17 and (purchase+purchaseCard)>=requiredPurchase").list(); 
    System.out.print((long)((System.nanoTime() - timeIter)/1000000) + "\t"); 

    timeIter = System.nanoTime(); 
    dao.createSQLQuery("select count(id) from stat_accounts_history where month='2013.01' and (purchase+purchaseCard)>=requiredPurchase").list(); 
    System.out.print((long)((System.nanoTime() - timeIter)/1000000) + "\t"); 

    timeIter = System.nanoTime(); 
    dao.createSQLQuery("select count(id) from stat_accounts_history where month='2013.09' and (purchase+purchaseCard)>=requiredPurchase").list(); 
    System.out.print((long)((System.nanoTime() - timeIter)/1000000) + "\t"); 

    System.out.println(); 
} 

而我看到的是（1-2列 - 分區表，3-4列 - 未分區表）：

1894 479 9 541  
436 442 2 2 
447 458 2 2 
469 469 2 2 
439 451 2 2 
468 453 3 2 

我試着用Hibernate和JDBC連接執行查詢 - 結果相同。

爲什麼查詢分區表的工作速度較慢？

Answer 1

我自己解決了這個問題。

1. ，則應該設置innodb_file_per_table = 1在my.cnf中。不支持在MySQL分區表
2. 查詢緩存 - http://dev.mysql.com/doc/refman/5.5/en/partitioning-limitations.html