JOIN 大表的 MySQL 查询优化

Question

我的 MySQL 查询有大数据访问问题，当使用 join 优化查询时，它会在 122 秒内给出一周数据的输出。然后对于一个月的数据，该过程需要 526 秒。 我想优化此查询以减少每年的处理时间，或者是否有任何方法可以总体上优化 MySQL 设置？

表的详细信息。 我引用了 mdiaries 和 tv_diaries 两个表，在两个表中我都索引了相关列，在 mdiaries 表中有 2661331 行和 tv_diaries 中有 27074645 行。

日记表:

  INDEX area (area),
  INDEX date (date),
  INDEX district (district),
  INDEX gaDivision (gaDivision),
  INDEX member_id (member_id),
  INDEX tv_channel_id (tv_channel_id),

电视日记。

  INDEX area (area),
  INDEX date (date),
  INDEX district (district),
  INDEX member_id (member_id),
  INDEX timeslot_id (timeslot_id),
  INDEX tv_channel_id (tv_channel_id),

这是我的查询，执行需要 122 秒。

$sql = "SELECT COUNT(TvDiary.id) AS m_count,TvDiary.date,TvDiary.timeslot_id,TvDiary.tv_channel_id,TvDiary.district,TvDiary.area
FROM `mdiaries` AS Mdiary INNER JOIN `tv_diaries` AS TvDiary ON Mdiary.member_id = TvDiary.member_id
WHERE Mdiary.date >= '2014-01-01' AND Mdiary.date <= '2014-01-07'
AND TvDiary.date >= '2014-01-01' AND TvDiary.date <= '2014-01-07'
GROUP BY TvDiary.date,
TvDiary.timeslot_id,
TvDiary.tv_channel_id,
TvDiary.district,
TvDiary.area";

这是我的.cnf文件。

    [mysqld]

## General
datadir                         = /var/lib/mysql
tmpdir                          = /var/lib/mysqltmp
socket                          = /var/lib/mysql/mysql.sock
skip-name-resolve
sql-mode                        = NO_ENGINE_SUBSTITUTION
#event-scheduler                = 1

## Networking
back-log                        = 100
#max-connections                = 200
max-connect-errors              = 10000
max-allowed-packet              = 32M
interactive-timeout             = 3600
wait-timeout                    = 600

### Storage Engines
#default-storage-engine         = InnoDB
innodb                          = FORCE

## MyISAM
key-buffer-size                 = 64M
myisam-sort-buffer-size         = 128M

## InnoDB
innodb-buffer-pool-size        = 16G
innodb_buffer_pool_instances    = 16
#innodb-log-file-size           = 100M
#innodb-log-buffer-size         = 8M
#innodb-file-per-table          = 1
#innodb-open-files              = 300

## Replication
server-id                       = 1
#log-bin                        = /var/log/mysql/bin-log
#relay-log                      = /var/log/mysql/relay-log
relay-log-space-limit           = 16G
expire-logs-days                = 7
#read-only                      = 1
#sync-binlog                    = 1
#log-slave-updates              = 1
#binlog-format                  = STATEMENT
#auto-increment-offset          = 1
#auto-increment-increment       = 2

## Logging
log-output                      = FILE
slow-query-log                  = 1
slow-query-log-file             = /var/log/mysql/slow-log
#log-slow-slave-statements
long-query-time                 = 2

##
query_cache_size        = 512M
query_cache_type        = 1
query_cache_limit       = 2M
join_buffer_size        = 512M
thread_cache_size       = 128

[mysqld_safe]
log-error                       = /var/log/mysqld.log
open-files-limit                = 65535

[mysql]
no-auto-rehash

Answer 1

这是您的查询:

SELECT COUNT(t.id) AS m_count, t.date, t.timeslot_id, t.tv_channel_id,
       t.district, t.area
FROM `mdiaries` m INNER JOIN
     `tv_diaries` t
     ON m.member_id = t.member_id
WHERE m.date >= '2014-01-01' AND m.date <= '2014-01-07' AND
      t.date >= '2014-01-01' AND t.date <= '2014-01-07'
GROUP BY t.date, t.timeslot_id, t.tv_channel_id, t.district, t.area;

我将从复合索引开始:tv_diaries(date, member_id) 和 mdiaries(member_id, date)。

此查询有问题，但这些可能会有所帮助。