差不多3億6千萬數據，需要去重。因為數據量太大，所以：

將數據load data infile到大表里，不進行任何去重操作，沒有任何約束。然后將數據分成幾十個小表，用這幾十個小表去對比大表去重。得到去重后的小表。去重以后的小表，根據字段進行hash算出后兩位數字，重新建好新表，將去重后小表的數據，插入到帶有hash數字新表中。

存儲過程如下(去重)：

DELIMITER //

/*tblname 動態控制表名*/

CREATE PROCEDURE create_imsi(IN tblname varchar(200))

begin

declare age int default 1;

declare done int(1) default 0;

declare v_imsi varchar(200);

/*定義游標*/

declare cur_l cursor for select imsi from sqlstr;

/*定義異常*/

DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' set done=1;

drop view if exists sqlstr;

/*定義視圖*/

set @tbl = CONCAT("create view sqlstr as select a.imsi from tbl_new a,(select imsi from phone_",tblname," group by imsi having count(imsi) > 1) b where a.imsi = b.imsi group by imsi");

/*執行視圖語句*/

PREPARE stmt FROM @tbl;

EXECUTE stmt;

DEALLOCATE PREPARE stmt;

OPEN cur_l;

FETCH cur_l INTO v_imsi;

while (done <> 1)

do

/*對比大表數據，刪除小表中的重復數據*/

set @del = CONCAT("delete from phone_",tblname," where imsi=",v_imsi);

PREPARE stmt1 FROM @del;

EXECUTE stmt1;

DEALLOCATE PREPARE stmt1;

FETCH cur_l INTO v_imsi;

end while;

close cur_l;

end//

DELIMITER ;

2、根據hash算法插入新表：

DELIMITER //

CREATE PROCEDURE insert_imsi(IN tblname varchar(20))

begin

declare age int default 1;

declare done int(1) default 0;

declare done1 int(1) default 0;

declare v_imsi varchar(200);

declare v_e varchar(2000);

declare v_number varchar(3000);

declare v_ctype varchar(2000);

declare cur_l cursor for select split from sqlstr;

DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' set done=1;

DECLARE CONTINUE HANDLER FOR 1146 set done1=3;

DECLARE CONTINUE HANDLER FOR SQLSTATE '23000' set done1=1;

DECLARE CONTINUE HANDLER FOR SQLSTATE '42000' set done1=2;

DECLARE CONTINUE HANDLER FOR SQLSTATE 'HY000' set done1=3;

drop view if exists sqlstx;

drop view if exists sqlstr;

set @sqlstx = CONCAT("create view sqlstr as SELECT imsi,number,ctype,mod(conv(right(md5(imsi),2),16,10),100) split from imsi_phone_",tblname);

PREPARE stmt1 FROM @sqlstx;

EXECUTE stmt1;

DEALLOCATE PREPARE stmt1;

OPEN cur_l;

WHILE done <> 1

DO

FETCH cur_l INTO v_e;

set @ins = concat("insert into imsi_",v_e,"(imsi,number,ctype) select imsi,number,ctype from sqlstr where split = '",v_e,"'");

PREPARE stmt3 FROM @ins;

EXECUTE stmt3;

END WHILE;

close cur_l;

end//

DELIMITER ;

報錯：1、ERROR 1243 (HY000) at line 1: Unknown prepared statement handler (stmt3) given to EXECUTE

2、ERROR 1054 (42S22) at line 1: Unknown column '000cdc41b2a02518' in 'where clause'

由于set @dat = concat("insert into imsi_",v_e,"(imsi,number,ctype) select imsi,number,ctype from imsi_phone_",tblname," where imsi=‘’",v_imsi，“‘’”);沒有在(=)那里加單引號，因為字段里有字母。

參數優化：

由于建表使用innodb引擎，所以此優化是針對innodb引擎的：

1、innodb_flush_log_at_trx_commit參數設置為0，減少刷新。

2、set?sql_log_bin=0　　暫時不產生二進制日志

3、sync_binlog　　設置為0，減少刷新

4、innodb_buffer_pool_size　　　　盡可能設置最大

5、set foreign_key_checks=0　　去除外鍵檢查

6、減少不必要的索引，有重復數據的話，主鍵是必須要的

7、innodb_change_buffer_max_size　　　　上限為50，這里我設置為40，因為load是插入數據，所以設置插入緩沖

8、binlog_cache_size　　如果必須要開啟二進制日志，設置此參數盡可能大

9、innodb_flush_method　　　　刷新模式，設置為O_DIRECT

10、innodb_io_capacity　　　　刷新臟頁，根據你的硬盤設置

11、innodb_log_buffer_size　　盡可能設置最大

12、unique_checks　　設置為不檢查：set?unique_checks=0;

13、alter table tablename disable keys;設置表忽略索引，如果有。

總結

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