我为朋友开发了一个用于记录游戏统计数据的小应用程序。 起初它的表现相当不错，但现在我的snapshot_details表包含近55,000行，查看wide_snapshots视图的前25行需要28秒。
有没有人可以帮助我优化这种怪物？
查看wide_snapshots：
select `s`.`id_snapshot` AS `s_id_snapshot`,
`s`.`ref_player` AS `s_ref_player`,
`s`.`ref_world` AS `s_ref_world`,
`s`.`ref_alliance` AS `s_ref_alliance`,
`s`.`alliance_role` AS `s_alliance_role`,
`s`.`classe` AS `s_classe`,
unix_timestamp(`s`.`timestamp`) AS `s_timestamp`,
`s`.`rank` AS `s_rank`,
`s`.`is_substitution` AS `s_is_substitution`,
`s`.`nb_off_bases` AS `s_nb_off_bases`,
`s`.`moy_defense` AS `s_moy_defense`,
`s`.`nb_sup_bases` AS `s_nb_sup_bases`,
`s`.`moy_sup_lvl` AS `s_moy_sup_lvl`,
`s`.`moy_def_facility` AS `s_moy_def_facility`,
`s`.`max_cp` AS `s_max_cp`,
`s`.`research_points` AS `s_research_points`,
`s`.`supply_points` AS `s_supply_points`,
`s`.`command_points` AS `s_command_points`,
`s`.`credits` AS `s_credits`,
`s`.`max_repa` AS `s_max_repa`,
`s`.`nb_bases` AS `s_nb_bases`,
`s`.`prod_credit` AS `s_prod_credit`,
`s`.`prod_tiberium` AS `s_prod_tiberium`,
`s`.`prod_crystal` AS `s_prod_crystal`,
`s`.`prod_energy` AS `s_prod_energy`,
`s`.`base1_lvl` AS `s_base1_lvl`,
`s`.`base1_def` AS `s_base1_def`,
`s`.`base1_off` AS `s_base1_off`,
`s`.`base1_prod_energy` AS `s_base1_prod_energy`,
`s`.`base1_avia_repa` AS `s_base1_avia_repa`,
`s`.`base1_vehi_repa` AS `s_base1_vehi_repa`,
`s`.`base1_inf_repa` AS `s_base1_inf_repa`,
`s`.`base2_lvl` AS `s_base2_lvl`,
`s`.`base2_def` AS `s_base2_def`,
`s`.`base2_off` AS `s_base2_off`,
`s`.`base2_prod_energy` AS `s_base2_prod_energy`,
`s`.`base2_avia_repa` AS `s_base2_avia_repa`,
`s`.`base2_vehi_repa` AS `s_base2_vehi_repa`,
`s`.`base2_inf_repa` AS `s_base2_inf_repa`,
`sd`.`id_detail` AS `sd_id_detail`,
`sd`.`ref_snapshot` AS `sd_ref_snapshot`,
`sd`.`ingame_id` AS `sd_ingame_id`,
`sd`.`base_id` AS `sd_base_id`,
`sd`.`base_name` AS `sd_base_name`,
`sd`.`base_lvl` AS `sd_base_lvl`,
`sd`.`base_off` AS `sd_base_off`,
`sd`.`base_def` AS `sd_base_def`,
`sd`.`construction_yard` AS `sd_construction_yard`,
`sd`.`defense_facility` AS `sd_defense_facility`,
`sd`.`defense_hq` AS `sd_defense_hq`,
`sd`.`command_center` AS `sd_command_center`,
`sd`.`support_lvl` AS `sd_support_lvl`,
`sd`.`support_type` AS `sd_support_type`,
`sd`.`prod_credit` AS `sd_prod_credit`,
`sd`.`prod_energy` AS `sd_prod_energy`,
`sd`.`prod_tiberium` AS `sd_prod_tiberium`,
`sd`.`prod_crystal` AS `sd_prod_crystal`,
`p`.`ingame_id` AS `p_ingame_id`,
`p`.`name` AS `p_name`,
`a`.`ingame_id` AS `a_ingame_id`,
`a`.`name` AS `a_name`
from (
(
(
`kakawi_basetracker`.`snapshots` `s`
join `kakawi_basetracker`.`snapshot_details` `sd`
on `s`.`id_snapshot` = `sd`.`ref_snapshot`
)
join `kakawi_basetracker`.`players` `p`
on `s`.`ref_player` = `p`.`id_player`
)
join `kakawi_basetracker`.`alliances` `a`
on `s`.`ref_alliance` = `a`.`id_alliance`
)
where (
`s`.`id_snapshot` = (
select `s2`.`id_snapshot`
from `kakawi_basetracker`.`snapshots` `s2`
where (
(`s2`.`ref_player` = `s`.`ref_player`) and (`s2`.`ref_world` = `s`.`ref_world`) and (`s2`.`timestamp` > (now() - interval 5 day))
)
order by `s2`.`id_snapshot` desc limit 1
)
)
order by `p`.`name`,`s`.`ref_world`,`sd`.`base_id`
表格快照：
CREATE TABLE `snapshots` (
`id_snapshot` int(10) unsigned zerofill NOT NULL AUTO_INCREMENT,
`ref_player` smallint(5) unsigned zerofill NOT NULL,
`ref_world` smallint(10) unsigned zerofill NOT NULL,
`ref_alliance` smallint(10) unsigned zerofill DEFAULT NULL,
`alliance_role` varchar(32) DEFAULT NULL,
`classe` enum('GDI','NOD') NOT NULL,
`timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`ip_address` varchar(64) NOT NULL DEFAULT '0.0.0.0',
`rank` smallint(5) unsigned NOT NULL,
`is_substitution` tinyint(1) NOT NULL,
`nb_off_bases` tinyint(3) unsigned NOT NULL,
`moy_defense` decimal(5,2) unsigned NOT NULL,
`nb_sup_bases` tinyint(3) unsigned NOT NULL,
`moy_sup_lvl` decimal(5,2) unsigned NOT NULL,
`moy_def_facility` decimal(5,2) unsigned NOT NULL,
`max_cp` smallint(5) unsigned NOT NULL,
`research_points` bigint(20) unsigned NOT NULL,
`supply_points` smallint(5) unsigned NOT NULL,
`command_points` mediumint(8) unsigned NOT NULL,
`credits` bigint(20) unsigned NOT NULL,
`max_repa` smallint(5) unsigned NOT NULL,
`nb_bases` tinyint(3) unsigned NOT NULL,
`prod_credit` bigint(20) unsigned NOT NULL,
`prod_tiberium` bigint(20) unsigned NOT NULL,
`prod_crystal` bigint(20) unsigned NOT NULL,
`prod_energy` bigint(20) unsigned NOT NULL,
`base1_lvl` decimal(5,2) unsigned NOT NULL,
`base1_def` decimal(5,2) unsigned NOT NULL,
`base1_off` decimal(5,2) unsigned NOT NULL,
`base1_prod_energy` bigint(20) unsigned NOT NULL,
`base1_avia_repa` mediumint(8) unsigned NOT NULL,
`base1_vehi_repa` mediumint(8) unsigned NOT NULL,
`base1_inf_repa` mediumint(8) unsigned NOT NULL,
`base2_lvl` decimal(5,2) unsigned NOT NULL,
`base2_def` decimal(5,2) unsigned NOT NULL,
`base2_off` decimal(5,2) unsigned NOT NULL,
`base2_prod_energy` bigint(20) unsigned NOT NULL,
`base2_avia_repa` mediumint(8) unsigned NOT NULL,
`base2_vehi_repa` mediumint(8) unsigned NOT NULL,
`base2_inf_repa` mediumint(8) unsigned NOT NULL,
PRIMARY KEY (`id_snapshot`),
KEY `snapshots_ref_player_idx` (`ref_player`),
KEY `snapshots_ref_alliance_idx` (`ref_alliance`),
KEY `snapshots_ref_world_idx` (`ref_world`),
KEY `snapshots_ref_player_ref_world_timestamp_idx` (`ref_player`,`ref_world`,`timestamp`),
CONSTRAINT `snapshots_ref_alliance_fkey` FOREIGN KEY (`ref_alliance`) REFERENCES `alliances` (`id_alliance`) ON DELETE SET NULL ON UPDATE CASCADE,
CONSTRAINT `snapshots_ref_player_fkey` FOREIGN KEY (`ref_player`) REFERENCES `players` (`id_player`) ON DELETE CASCADE ON UPDATE CASCADE,
CONSTRAINT `snapshots_ref_world_fkey` FOREIGN KEY (`ref_world`) REFERENCES `worlds` (`id_world`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=12162 DEFAULT CHARSET=utf8
表snapshot_details：
CREATE TABLE `snapshot_details` (
`id_detail` bigint(20) unsigned zerofill NOT NULL AUTO_INCREMENT,
`ref_snapshot` int(10) unsigned zerofill NOT NULL,
`ingame_id` int(10) unsigned NOT NULL,
`base_id` tinyint(3) unsigned NOT NULL,
`base_name` varchar(256) NOT NULL,
`base_lvl` decimal(5,2) unsigned NOT NULL,
`base_off` decimal(5,2) unsigned NOT NULL,
`base_def` decimal(5,2) unsigned NOT NULL,
`construction_yard` tinyint(3) unsigned NOT NULL,
`defense_facility` tinyint(3) unsigned NOT NULL,
`defense_hq` tinyint(3) unsigned NOT NULL,
`command_center` tinyint(3) unsigned NOT NULL,
`support_lvl` tinyint(3) unsigned NOT NULL,
`support_type` enum('Ion','Air','Art') DEFAULT NULL,
`prod_credit` int(10) unsigned NOT NULL,
`prod_energy` int(10) unsigned NOT NULL,
`prod_tiberium` int(10) unsigned NOT NULL,
`prod_crystal` int(10) unsigned NOT NULL,
PRIMARY KEY (`id_detail`),
UNIQUE KEY `snapshot_details_ref_snapshot_base_id_uniq` (`ref_snapshot`,`base_id`) USING BTREE,
CONSTRAINT `snapshot_details_ref_snapshot_fkey` FOREIGN KEY (`ref_snapshot`) REFERENCES `snapshots` (`id_snapshot`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=61299 DEFAULT CHARSET=utf8
表格球员：
CREATE TABLE `players` (
`id_player` smallint(5) unsigned zerofill NOT NULL AUTO_INCREMENT,
`ingame_id` int(5) unsigned NOT NULL,
`name` varchar(64) NOT NULL,
PRIMARY KEY (`id_player`),
UNIQUE KEY `players_ingame_id_uniq` (`ingame_id`)
) ENGINE=InnoDB AUTO_INCREMENT=200 DEFAULT CHARSET=utf8
表联盟：
CREATE TABLE `alliances` (
`id_alliance` smallint(5) unsigned zerofill NOT NULL AUTO_INCREMENT,
`ingame_id` smallint(5) unsigned NOT NULL,
`ref_world` smallint(5) unsigned zerofill NOT NULL,
`name` varchar(64) NOT NULL,
PRIMARY KEY (`id_alliance`),
UNIQUE KEY `alliances_ingame_id_ref_world_uniq` (`ingame_id`,`ref_world`) USING BTREE,
KEY `alliances_ref_world_fkey` (`ref_world`),
CONSTRAINT `alliances_ref_world_fkey` FOREIGN KEY (`ref_world`) REFERENCES `worlds` (`id_world`)
) ENGINE=InnoDB AUTO_INCREMENT=203 DEFAULT CHARSET=utf8
用原始查询解释：
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY p ALL PRIMARY NULL NULL NULL 197 Using temporary; Using filesort
1 PRIMARY s ref PRIMARY,snapshots_ref_player_idx,snapshots_ref_all... snapshots_ref_player_idx 2 kakawi_basetracker.p.id_player 27 Using where
1 PRIMARY a eq_ref PRIMARY PRIMARY 2 kakawi_basetracker.s.ref_alliance 1
1 PRIMARY sd ref snapshot_details_ref_snapshot_base_id_uniq snapshot_details_ref_snapshot_base_id_uniq 4 func 2 Using where
2 DEPENDENT SUBQUERY s2 index snapshots_ref_player_idx,snapshots_ref_world_idx PRIMARY 4 NULL 1 Using where
解释user4621032的建议：
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 899 Using where; Using temporary; Using filesort
1 PRIMARY a eq_ref PRIMARY PRIMARY 2 s.ref_alliance 1
1 PRIMARY p eq_ref PRIMARY PRIMARY 2 s.ref_player 1
1 PRIMARY sd ref snapshot_details_ref_snapshot_base_id_uniq snapshot_details_ref_snapshot_base_id_uniq 4 func 2 Using where
3 DEPENDENT SUBQUERY s2 index snapshots_ref_player_idx,snapshots_ref_world_idx PRIMARY 4 NULL 1 Using where
2 DERIVED snapshots ALL NULL NULL NULL NULL 11898 Using where
答案 0 :(得分：1)
这样的事情： 在过去五天内选择所需的记录记录。然后从中选择所需的记录，然后加入所需的表记录。
select
.....
from (
(
(
(select * from `kakawi_basetracker`.`snapshots` where `timestamp` > (now() - interval 5 day)) `s`
join `kakawi_basetracker`.`snapshot_details` `sd`
on `s`.`id_snapshot` = `sd`.`ref_snapshot`
)
join `kakawi_basetracker`.`players` `p`
on `s`.`ref_player` = `p`.`id_player`
)
join `kakawi_basetracker`.`alliances` `a`
on `s`.`ref_alliance` = `a`.`id_alliance`
)
where (
`s`.`id_snapshot` = (
select `s2`.`id_snapshot`
from `kakawi_basetracker`.`snapshots` `s2`
where (
(`s2`.`ref_player` = `s`.`ref_player`) and (`s2`.`ref_world` = `s`.`ref_world`)
)
order by `s2`.`id_snapshot` desc limit 1
)
)
order by `p`.`name`,`s`.`ref_world`,`sd`.`base_id`
答案 1 :(得分：0)
添加此索引：
EXPLAIN SELECT ...VIEW运行速度比执行查询要慢吗？ （有时这是一个因素。）
请提供Dialog。