Q&A:
1.mul key:
1. 如果Key是空的, 那么該列值的可以重復, 表示該列沒有索引, 或者是一個非唯一的復合索引的非前導列 2. 如果Key是PRI, 那么該列是主鍵的組成部分 3. 如果Key是UNI, 那么該列是一個唯一值索引的第一列(前導列),並別不能含有空值(NULL) 4. 如果Key是MUL, 那么該列的值可以重復, 該列是一個非唯一索引的前導列(第一列)或者是一個唯一性索引的組成部分但是可以含有空值NULL
2.mysql分區表概述:
參考: https://dev.mysql.com/doc/refman/5.1/zh/partitioning.html 分區表分為四種: range分區:基於屬於一個給定連續區間的列值,把多行分配給分區 list分區:類似於按RANGE分區,區別在於LIST分區是基於列值匹配一個離散值集合中的某個值來進行選擇 hash分區:基於用戶定義的表達式的返回值來進行選擇的分區,該表達式使用將要插入到表中的這些行的列值進行計算 key分區:類似於按HASH分區,區別在於KEY分區只支持計算一列或多列 常用的是range和list分區 無論使用何種類型的分區,分區總是在創建時就自動的順序編號,且從0開始記錄,記住這一點非常重要。當有一新行插入到一個分區表中時,就是使用這些分區編號來識別正確的分區。 注1: 如果想在已經建好的表上進行分區,如果使用alter添加分區的話,mysql會提示錯誤: ERROR 1505 <HY000> Partition management on a not partitioned table is not possible 正確的方法是新建一個具有分區的表,結構一致,然后用insert into 分區表 select * from 原始表;
http://blog.sina.com.cn/s/blog_5f54f0be01015tag.html
預計過程:
1.停止mysql,/etc/init.d/mysql stop
2.記錄下要修改的表的表結構,
3.刪除表,
4.創建和之前表結構一致但帶有分區表的數據表
5.創建procedure,修改crontab
問題,修改之后,一段時間之前的數據會被刪除,但這些數據會不會被別的表引用;
測試過程:
http://zabbixzone.com/zabbix/partitioning-tables/
1.如果只做歷史表的每日分割,刪除如下表 history history_uint history_log history_str history_text 他們的創建語法是: root@InnerServer1:/home/silence/zabbix-2.2.2/database/mysql# mysql -uroot -pfengmao -e 'show create table zabbix.history\G show create table zabbix.history_uint\G show create table zabbix.history_log\G show create table zabbix.history_str\G show create table zabbix.history_text\G ' *************************** 1. row *************************** Table: history Create Table: CREATE TABLE `history` ( `itemid` bigint(20) unsigned NOT NULL, `clock` int(11) NOT NULL DEFAULT '0', `value` double(16,4) NOT NULL DEFAULT '0.0000', `ns` int(11) NOT NULL DEFAULT '0', KEY `history_1` (`itemid`,`clock`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin; *************************** 1. row *************************** Table: history_uint Create Table: CREATE TABLE `history_uint` ( `itemid` bigint(20) unsigned NOT NULL, `clock` int(11) NOT NULL DEFAULT '0', `value` bigint(20) unsigned NOT NULL DEFAULT '0', `ns` int(11) NOT NULL DEFAULT '0', KEY `history_uint_1` (`itemid`,`clock`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin; *************************** 1. row *************************** Table: history_log Create Table: CREATE TABLE `history_log` ( `id` bigint(20) unsigned NOT NULL, `itemid` bigint(20) unsigned NOT NULL, `clock` int(11) NOT NULL DEFAULT '0', `timestamp` int(11) NOT NULL DEFAULT '0', `source` varchar(64) COLLATE utf8_bin NOT NULL DEFAULT '', `severity` int(11) NOT NULL DEFAULT '0', `value` text COLLATE utf8_bin NOT NULL, `logeventid` int(11) NOT NULL DEFAULT '0', `ns` int(11) NOT NULL DEFAULT '0', PRIMARY KEY (`id`), UNIQUE KEY `history_log_2` (`itemid`,`id`), KEY `history_log_1` (`itemid`,`clock`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin; *************************** 1. row *************************** Table: history_str Create Table: CREATE TABLE `history_str` ( `itemid` bigint(20) unsigned NOT NULL, `clock` int(11) NOT NULL DEFAULT '0', `value` varchar(255) COLLATE utf8_bin NOT NULL DEFAULT '', `ns` int(11) NOT NULL DEFAULT '0', KEY `history_str_1` (`itemid`,`clock`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin; *************************** 1. row *************************** Table: history_text Create Table: CREATE TABLE `history_text` ( `id` bigint(20) unsigned NOT NULL, `itemid` bigint(20) unsigned NOT NULL, `clock` int(11) NOT NULL DEFAULT '0', `value` text COLLATE utf8_bin NOT NULL, `ns` int(11) NOT NULL DEFAULT '0', PRIMARY KEY (`id`), UNIQUE KEY `history_text_2` (`itemid`,`id`), KEY `history_text_1` (`itemid`,`clock`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin;
因為分區表使用的列必須為primary key,或者表沒有主鍵,所以需要修改如下表:
ALTER TABLE `history_log` DROP PRIMARY KEY, ADD PRIMARY KEY (`itemid`,`id`,`clock`);
ALTER TABLE `history_log` DROP KEY `history_log_2`;
ALTER TABLE `history_text` DROP PRIMARY KEY, ADD PRIMARY KEY (`itemid`,`id`,`clock`);
ALTER TABLE `history_text` DROP KEY `history_text_2`;
創建之前刪除的相應的表,並給他們加上分區,類似如下形式:
CREATE TABLE `history` ( `itemid` bigint(20) unsigned NOT NULL, `clock` int(11) NOT NULL DEFAULT '0', `value` double(16,4) NOT NULL DEFAULT '0.0000', `ns` int(11) NOT NULL DEFAULT '0', KEY `history_1` (`itemid`,`clock`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin partition by range(clock) ( PARTITION p20140310 VALUES LESS THAN (UNIX_TIMESTAMP("2014-03-10 00:00:00")) );
粘貼每日分區函數:
DELIMITER // DROP PROCEDURE IF EXISTS `zabbix`.`create_zabbix_partitions` // CREATE PROCEDURE `zabbix`.`create_zabbix_partitions` () BEGIN CALL zabbix.create_next_partitions("zabbix","history"); CALL zabbix.create_next_partitions("zabbix","history_log"); CALL zabbix.create_next_partitions("zabbix","history_str"); CALL zabbix.create_next_partitions("zabbix","history_text"); CALL zabbix.create_next_partitions("zabbix","history_uint"); CALL zabbix.drop_old_partitions("zabbix","history"); CALL zabbix.drop_old_partitions("zabbix","history_log"); CALL zabbix.drop_old_partitions("zabbix","history_str"); CALL zabbix.drop_old_partitions("zabbix","history_text"); CALL zabbix.drop_old_partitions("zabbix","history_uint"); END // DROP PROCEDURE IF EXISTS `zabbix`.`create_next_partitions` // CREATE PROCEDURE `zabbix`.`create_next_partitions` (SCHEMANAME varchar(64), TABLENAME varchar(64)) BEGIN DECLARE NEXTCLOCK timestamp; DECLARE PARTITIONNAME varchar(16); DECLARE CLOCK int; SET @totaldays = 7; SET @i = 1; createloop: LOOP SET NEXTCLOCK = DATE_ADD(NOW(),INTERVAL @i DAY); SET PARTITIONNAME = DATE_FORMAT( NEXTCLOCK, 'p%Y%m%d' ); SET CLOCK = UNIX_TIMESTAMP(DATE_FORMAT(DATE_ADD( NEXTCLOCK ,INTERVAL 1 DAY),'%Y-%m-%d 00:00:00')); CALL zabbix.create_partition( SCHEMANAME, TABLENAME, PARTITIONNAME, CLOCK ); SET @i=@i+1; IF @i > @totaldays THEN LEAVE createloop; END IF; END LOOP; END // DROP PROCEDURE IF EXISTS `zabbix`.`drop_old_partitions` // CREATE PROCEDURE `zabbix`.`drop_old_partitions` (SCHEMANAME varchar(64), TABLENAME varchar(64)) BEGIN DECLARE OLDCLOCK timestamp; DECLARE PARTITIONNAME varchar(16); DECLARE CLOCK int; SET @mindays = 3; SET @maxdays = @mindays+4; SET @i = @maxdays; droploop: LOOP SET OLDCLOCK = DATE_SUB(NOW(),INTERVAL @i DAY); SET PARTITIONNAME = DATE_FORMAT( OLDCLOCK, 'p%Y%m%d' ); CALL zabbix.drop_partition( SCHEMANAME, TABLENAME, PARTITIONNAME ); SET @i=@i-1; IF @i <= @mindays THEN LEAVE droploop; END IF; END LOOP; END // DROP PROCEDURE IF EXISTS `zabbix`.`create_partition` // CREATE PROCEDURE `zabbix`.`create_partition` (SCHEMANAME varchar(64), TABLENAME varchar(64), PARTITIONNAME varchar(64), CLOCK int) BEGIN DECLARE RETROWS int; SELECT COUNT(1) INTO RETROWS FROM `information_schema`.`partitions` WHERE `table_schema` = SCHEMANAME AND `table_name` = TABLENAME AND `partition_name` = PARTITIONNAME; IF RETROWS = 0 THEN SELECT CONCAT( "create_partition(", SCHEMANAME, ",", TABLENAME, ",", PARTITIONNAME, ",", CLOCK, ")" ) AS msg; SET @sql = CONCAT( 'ALTER TABLE `', SCHEMANAME, '`.`', TABLENAME, '`', ' ADD PARTITION (PARTITION ', PARTITIONNAME, ' VALUES LESS THAN (', CLOCK, '));' ); PREPARE STMT FROM @sql; EXECUTE STMT; DEALLOCATE PREPARE STMT; END IF; END // DROP PROCEDURE IF EXISTS `zabbix`.`drop_partition` // CREATE PROCEDURE `zabbix`.`drop_partition` (SCHEMANAME varchar(64), TABLENAME varchar(64), PARTITIONNAME varchar(64)) BEGIN DECLARE RETROWS int; SELECT COUNT(1) INTO RETROWS FROM `information_schema`.`partitions` WHERE `table_schema` = SCHEMANAME AND `table_name` = TABLENAME AND `partition_name` = PARTITIONNAME; IF RETROWS = 1 THEN SELECT CONCAT( "drop_partition(", SCHEMANAME, ",", TABLENAME, ",", PARTITIONNAME, ")" ) AS msg; SET @sql = CONCAT( 'ALTER TABLE `', SCHEMANAME, '`.`', TABLENAME, '`', ' DROP PARTITION ', PARTITIONNAME, ';' ); PREPARE STMT FROM @sql; EXECUTE STMT; DEALLOCATE PREPARE STMT; END IF; END // DELIMITER ;
最終的形式:
root@InnerServer1:/app/zabbix/sbin# mysql -uroot -pfengmao -e 'show create table zabbix.history\G show create table zabbix.history_uint\G show create table zabbix.history_log\G show create table zabbix.history_str\G show create table zabbix.history_text\G ' *************************** 1. row *************************** Table: history Create Table: CREATE TABLE `history` ( `itemid` bigint(20) unsigned NOT NULL, `clock` int(11) NOT NULL DEFAULT '0', `value` double(16,4) NOT NULL DEFAULT '0.0000', `ns` int(11) NOT NULL DEFAULT '0', KEY `history_1` (`itemid`,`clock`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin /*!50100 PARTITION BY RANGE (clock) (PARTITION p20140310 VALUES LESS THAN (1394380800) ENGINE = InnoDB, PARTITION p20140312 VALUES LESS THAN (1394640000) ENGINE = InnoDB, PARTITION p20140313 VALUES LESS THAN (1394726400) ENGINE = InnoDB, PARTITION p20140314 VALUES LESS THAN (1394812800) ENGINE = InnoDB, PARTITION p20140315 VALUES LESS THAN (1394899200) ENGINE = InnoDB, PARTITION p20140316 VALUES LESS THAN (1394985600) ENGINE = InnoDB, PARTITION p20140317 VALUES LESS THAN (1395072000) ENGINE = InnoDB, PARTITION p20140318 VALUES LESS THAN (1395158400) ENGINE = InnoDB) */ *************************** 1. row *************************** Table: history_uint Create Table: CREATE TABLE `history_uint` ( `itemid` bigint(20) unsigned NOT NULL, `clock` int(11) NOT NULL DEFAULT '0', `value` bigint(20) unsigned NOT NULL DEFAULT '0', `ns` int(11) NOT NULL DEFAULT '0', KEY `history_uint_1` (`itemid`,`clock`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin /*!50100 PARTITION BY RANGE (clock) (PARTITION p20140310 VALUES LESS THAN (1394380800) ENGINE = InnoDB, PARTITION p20140312 VALUES LESS THAN (1394640000) ENGINE = InnoDB, PARTITION p20140313 VALUES LESS THAN (1394726400) ENGINE = InnoDB, PARTITION p20140314 VALUES LESS THAN (1394812800) ENGINE = InnoDB, PARTITION p20140315 VALUES LESS THAN (1394899200) ENGINE = InnoDB, PARTITION p20140316 VALUES LESS THAN (1394985600) ENGINE = InnoDB, PARTITION p20140317 VALUES LESS THAN (1395072000) ENGINE = InnoDB, PARTITION p20140318 VALUES LESS THAN (1395158400) ENGINE = InnoDB) */ *************************** 1. row *************************** Table: history_log Create Table: CREATE TABLE `history_log` ( `id` bigint(20) unsigned NOT NULL, `itemid` bigint(20) unsigned NOT NULL, `clock` int(11) NOT NULL DEFAULT '0', `timestamp` int(11) NOT NULL DEFAULT '0', `source` varchar(64) COLLATE utf8_bin NOT NULL DEFAULT '', `severity` int(11) NOT NULL DEFAULT '0', `value` text COLLATE utf8_bin NOT NULL, `logeventid` int(11) NOT NULL DEFAULT '0', `ns` int(11) NOT NULL DEFAULT '0', PRIMARY KEY (`itemid`,`id`,`clock`), KEY `history_log_1` (`itemid`,`clock`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin /*!50100 PARTITION BY RANGE (clock) (PARTITION p20140310 VALUES LESS THAN (1394380800) ENGINE = InnoDB, PARTITION p20140312 VALUES LESS THAN (1394640000) ENGINE = InnoDB, PARTITION p20140313 VALUES LESS THAN (1394726400) ENGINE = InnoDB, PARTITION p20140314 VALUES LESS THAN (1394812800) ENGINE = InnoDB, PARTITION p20140315 VALUES LESS THAN (1394899200) ENGINE = InnoDB, PARTITION p20140316 VALUES LESS THAN (1394985600) ENGINE = InnoDB, PARTITION p20140317 VALUES LESS THAN (1395072000) ENGINE = InnoDB, PARTITION p20140318 VALUES LESS THAN (1395158400) ENGINE = InnoDB) */ *************************** 1. row *************************** Table: history_str Create Table: CREATE TABLE `history_str` ( `itemid` bigint(20) unsigned NOT NULL, `clock` int(11) NOT NULL DEFAULT '0', `value` varchar(255) COLLATE utf8_bin NOT NULL DEFAULT '', `ns` int(11) NOT NULL DEFAULT '0', KEY `history_str_1` (`itemid`,`clock`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin /*!50100 PARTITION BY RANGE (clock) (PARTITION p20140310 VALUES LESS THAN (1394380800) ENGINE = InnoDB, PARTITION p20140312 VALUES LESS THAN (1394640000) ENGINE = InnoDB, PARTITION p20140313 VALUES LESS THAN (1394726400) ENGINE = InnoDB, PARTITION p20140314 VALUES LESS THAN (1394812800) ENGINE = InnoDB, PARTITION p20140315 VALUES LESS THAN (1394899200) ENGINE = InnoDB, PARTITION p20140316 VALUES LESS THAN (1394985600) ENGINE = InnoDB, PARTITION p20140317 VALUES LESS THAN (1395072000) ENGINE = InnoDB, PARTITION p20140318 VALUES LESS THAN (1395158400) ENGINE = InnoDB) */ *************************** 1. row *************************** Table: history_text Create Table: CREATE TABLE `history_text` ( `id` bigint(20) unsigned NOT NULL, `itemid` bigint(20) unsigned NOT NULL, `clock` int(11) NOT NULL DEFAULT '0', `value` text COLLATE utf8_bin NOT NULL, `ns` int(11) NOT NULL DEFAULT '0', PRIMARY KEY (`itemid`,`id`,`clock`), KEY `history_text_1` (`itemid`,`clock`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin /*!50100 PARTITION BY RANGE (clock) (PARTITION p20140310 VALUES LESS THAN (1394380800) ENGINE = InnoDB, PARTITION p20140312 VALUES LESS THAN (1394640000) ENGINE = InnoDB, PARTITION p20140313 VALUES LESS THAN (1394726400) ENGINE = InnoDB, PARTITION p20140314 VALUES LESS THAN (1394812800) ENGINE = InnoDB, PARTITION p20140315 VALUES LESS THAN (1394899200) ENGINE = InnoDB, PARTITION p20140316 VALUES LESS THAN (1394985600) ENGINE = InnoDB, PARTITION p20140317 VALUES LESS THAN (1395072000) ENGINE = InnoDB, PARTITION p20140318 VALUES LESS THAN (1395158400) ENGINE = InnoDB) */ root@InnerServer1:/app/zabbix/sbin#