保留意见。将尝试更广泛的综合索引。@LightnessRacesinOrbit-MariaDB 10.2和MySQL 5.7可能会改进您可以使用的优化器。请努力摆脱古董5.1。当然期待这一天。不过,这不在我的控制范围之内,除非我们开始发布从源代码构建的My
保留意见。将尝试更广泛的综合索引。@LightnessRacesinOrbit-MariaDB 10.2和MySQL 5.7可能会改进您可以使用的优化器。请努力摆脱古董5.1。当然期待这一天。不过,这不在我的控制范围之内,除非我们开始发布从源代码构建的My,mysql,indexing,mariadb,innodb,Mysql,Indexing,Mariadb,Innodb,保留意见。将尝试更广泛的综合索引。@LightnessRacesinOrbit-MariaDB 10.2和MySQL 5.7可能会改进您可以使用的优化器。请努力摆脱古董5.1。当然期待这一天。不过,这不在我的控制范围之内,除非我们开始发布从源代码构建的MySQL,我不想开始这样做,而且我不相信我们的安全过度敏感的客户会接受退出回购。@LightnessRacesinOrbit-根据我的建议尽你所能,然后返回以获取更多建议/滥用。提醒您的客户,自4年前5.1进入EOL(生命周期结束)以来,安全修补
保留意见。将尝试更广泛的综合索引。@LightnessRacesinOrbit-MariaDB 10.2和MySQL 5.7可能会改进您可以使用的优化器。请努力摆脱古董5.1。当然期待这一天。不过,这不在我的控制范围之内,除非我们开始发布从源代码构建的MySQL,我不想开始这样做,而且我不相信我们的安全过度敏感的客户会接受退出回购。@LightnessRacesinOrbit-根据我的建议尽你所能,然后返回以获取更多建议/滥用。提醒您的客户,自4年前5.1进入EOL(生命周期结束)以来,安全修补程序尚未重新移植到5.1中:。
CREATE TABLE `Alarms` (
`AlarmId` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
`DeviceId` BINARY(16) NOT NULL,
`Code` BIGINT(20) UNSIGNED NOT NULL,
`Ended` TINYINT(1) NOT NULL DEFAULT '0',
`NaturalEnd` TINYINT(1) NOT NULL DEFAULT '0',
`Pinned` TINYINT(1) NOT NULL DEFAULT '0',
`Acknowledged` TINYINT(1) NOT NULL DEFAULT '0',
`StartedAt` TIMESTAMP NOT NULL DEFAULT '0000-00-00 00:00:00',
`EndedAt` TIMESTAMP NULL DEFAULT NULL,
`MarkedForDeletion` TINYINT(1) NOT NULL DEFAULT '0',
PRIMARY KEY (`AlarmId`),
KEY `Key1` (`Ended`,`Acknowledged`),
KEY `Key2` (`Pinned`),
KEY `Key3` (`DeviceId`,`Pinned`),
KEY `Key4` (`DeviceId`,`StartedAt`,`EndedAt`),
KEY `Key5` (`DeviceId`,`Ended`,`EndedAt`),
KEY `Key6` (`MarkedForDeletion`)
) ENGINE=INNODB;
-- Populate some dummy data; 500 alarms for each
-- of 1000 one-second periods
SET @testDevice = UNHEX('00030000000000000000000000000000');
DROP PROCEDURE IF EXISTS `injectAlarms`;
DELIMITER ;;CREATE PROCEDURE injectAlarms()
BEGIN
SET @fromdate = '2018-02-18 00:00:00';
SET @numdates = 1000;
SET @todate = DATE_ADD(@fromdate, INTERVAL @numdates SECOND);
-- Create table of alarm codes to join on
DROP TABLE IF EXISTS `__codes`;
CREATE TEMPORARY TABLE `__codes` (
`Code` BIGINT NOT NULL PRIMARY KEY
);
SET @startcode = 0;
SET @endcode = 499;
REPEAT
INSERT INTO `__codes` VALUES(@startcode);
SET @startcode = @startcode + 1;
UNTIL @startcode > @endcode END REPEAT;
-- Add an alarm for each code, for each second in range
REPEAT
INSERT INTO `Alarms`
(`DeviceId`, `Code`, `Ended`, `NaturalEnd`, `Pinned`, `Acknowledged`, `StartedAt`, `EndedAt`)
SELECT
@testDevice,
`Code`,
TRUE, FALSE, FALSE, FALSE,
@fromdate, @fromdate
FROM `__codes`;
SET @fromdate = DATE_ADD(@fromdate, INTERVAL 1 SECOND);
UNTIL @fromdate > @todate END REPEAT;
END;;
DELIMITER ;
CALL injectAlarms();
SELECT * FROM `Alarms`
WHERE
((`Alarms`.`Ended` = FALSE AND `Alarms`.`Acknowledged` = FALSE) OR `Alarms`.`Pinned` = TRUE) AND
`MarkedForDeletion` = FALSE AND
`DeviceId` = @testDevice
;
id select_type table type possible_keys
1 SIMPLE Alarms index_merge Key1,Key2,Key3,Key4,Key5,Key6
key key_len ref rows Extra
Key1,Key2,Key3 2,1,17 (NULL) 2 Using union(Key1,intersect(Key2,Key3)); Using where
SELECT * FROM `Alarms`
WHERE
((`Alarms`.`Ended` = TRUE OR `Alarms`.`Acknowledged` = TRUE) AND `Alarms`.`Pinned` = FALSE) AND
`MarkedForDeletion` = FALSE AND
`DeviceId` = @testDevice
;
id select_type table type possible_keys
1 SIMPLE Alarms ref Key1,Key2,Key3,Key4,Key5,Key6
key key_len ref rows Extra
Key2 1 const 144706 Using where
-- Create a temporary table that we'll join against in a mo
DROP TABLE IF EXISTS `_ranges`;
CREATE TEMPORARY TABLE `_ranges` (
`Start` TIMESTAMP NOT NULL DEFAULT 0,
`End` TIMESTAMP NOT NULL DEFAULT 0,
PRIMARY KEY(`Start`, `End`)
);
-- Populate it (in reality this is performed by my application layer)
SET @endtime = 1518992216;
SET @starttime = @endtime - 86400;
SET @inter = 900;
DROP PROCEDURE IF EXISTS `populateRanges`;
DELIMITER ;;CREATE PROCEDURE populateRanges()
BEGIN
REPEAT
INSERT IGNORE INTO `_ranges` VALUES(FROM_UNIXTIME(@starttime),FROM_UNIXTIME(@starttime + @inter));
SET @starttime = @starttime + @inter;
UNTIL @starttime > @endtime END REPEAT;
END;;
DELIMITER ;CALL populateRanges();
-- Actual query
SELECT UNIX_TIMESTAMP(`_ranges`.`Start`) AS `Start_TS`,
COUNT(`Alarms`.`AlarmId`) AS `n`
FROM `_ranges`
LEFT JOIN `Alarms`
ON `Alarms`.`StartedAt` < `_ranges`.`End`
AND (`Alarms`.`EndedAt` IS NULL OR `Alarms`.`EndedAt` >= `_ranges`.`Start`)
AND ((`Alarms`.`EndedAt` IS NULL AND `Alarms`.`Acknowledged` = FALSE) OR `Alarms`.`Pinned` = TRUE)
-- Again, the above condition is sometimes replaced by:
-- AND ((`Alarms`.`EndedAt` IS NOT NULL OR `Alarms`.`Acknowledged` = TRUE) AND `Alarms`.`Pinned` = FALSE)
AND `DeviceId` = @testDevice
AND `MarkedForDeletion` = FALSE
GROUP BY `_ranges`.`Start`