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我運行一個非常簡單的MySQL數據庫構造。我只有像 id，TimeStamp和OP_fs155e列，我認爲這是極其 基本設置。MySQL在Centos 7中性能不佳7
MariaDB [gadbdfm]> desc optical_power;
+-----------+------------------+------+-----+----------------------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+------------------+------+-----+----------------------+-----------------------------+
| id_record | int(10) unsigned | NO | PRI | NULL | auto_increment |
| TimeStamp | timestamp(6) | NO | | CURRENT_TIMESTAMP(6) | on update CURRENT_TIMESTAMP |
| OP_fs155e | varchar(30) | YES | MUL | NULL | |
| data1 | varchar(30) | YES | | NULL | |
| data2 | varchar(30) | YES | | NULL | |
| data3 | varchar(30) | YES | | NULL | |
| data4 | varchar(30) | YES | | NULL | |
| data5 | varchar(30) | YES | | NULL | |
+-----------+------------------+------+-----+----------------------+-----------------------------+
8 rows in set (0.00 sec)
然而，我開始注意到，我的選擇是在 樹莓裨3（作爲主）和Centos7（如從屬 - 8GB肌肉服務器）第一非常緩慢。 這是我選擇在奴隸服務器花了幾分鐘的一切。我認爲問題在於Raspberry Pi 3速度太慢，但是當我發現它在真正的服務器從服務器上是一樣的時候，確切地說它有什麼問題。
MariaDB [gadbdfm]> select TimeStamp,OP_fs155e from optical_power;
| 2017-01-01 17:41:03.697000 | -24 |
| 2017-01-01 17:42:03.666000 | -24 |
| 2017-01-01 17:43:03.701000 | -24 |
| 2017-01-01 17:44:03.675000 | -24 |
| 2017-01-01 17:45:03.676000 | -24 |
| 2017-01-01 17:46:03.692000 | -24 |
| 2017-01-01 17:47:03.686000 | -24 |
| 2017-01-01 17:48:03.539000 | -24 |
| 2017-01-01 17:49:03.581000 | -24 |
+----------------------------+-----------+
23044062 rows in set (37.24 sec)
大師的my.cnf
[email protected] - /opt/FlightStrata155E cat /etc/mysql/mysql.conf.d/mysqld.cnf | grep -v "#" | grep -v "^$"
[mysqld_safe]
socket = /var/run/mysqld/mysqld.sock
nice = 0
[mysqld]
user = mysql
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
port = 3306
basedir = /usr
datadir = /var/lib/mysql
tmpdir = /tmp
lc-messages-dir = /usr/share/mysql
skip-external-locking
bind-address = 0.0.0.0
key_buffer_size = 16M
max_allowed_packet = 16M
thread_stack = 192K
thread_cache_size = 8
myisam-recover = BACKUP
query_cache_limit = 1M
query_cache_size = 16M
log_error = /var/log/mysql/error.log
server-id = 1
log_bin = /var/log/mysql/mysql-bin.log
expire_logs_days = 10
max_binlog_size = 100M
relay-log = /var/lib/mysql/mysql-relay-bin
relay-log-index = /var/lib/mysql/mysql-relay-bin.index
log-error = /var/lib/mysql/mysql.err
從my.cnf文件：
[[email protected] ~]# cat /etc/my.cnf | grep -v "#" | grep -v "^$"
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
symbolic-links=0
server-id = 2
[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid
!includedir /etc/my.cnf.d
我知道，我在我的計劃零優化。
再舉一個例子：
這對樹莓派3選擇需要像7分鐘
mysql> select TimeStamp, OP_fs155e from optical_power ORDER BY TimeStamp desc limit 15;
向我們展示來自**的輸出從optical_power ORDER EXPLAIN選擇時間戳，OP_fs155e按時間戳降序極限15; ** –
好了，所以什麼我的應用程序是這樣的：像每分鐘我收集我所說的價值**自由空間光學器件的OP_fs155e **（光功率），並將其保存在樹莓派（MASTER）的** mysql **中。 – user2156115