在linux上安裝5.6版本的mysql後，發現記憶體達到700M，經過一番上網查詢發現下面的設定可以減少記憶體:

[mysqld]
performance_schema_max_table_instances=400         
table_definition_cache=400                         
table_open_cache=256 

重啟mysql後記憶體減少到380m，雖然依然很大，也勉強可以使用了。

隨後繼續查資料發現其實mysql的安裝目錄share下就有各種不同需求的my.cnf配置，直接copy過來改名my.cnf就可以使用了

my-huge.cnf
This is for a large system with memory of 1G-2G where the system runs mainly.

my-innodb-heavy-4G.cnf
#DESCR: 4GB RAM, InnoDB only, ACID, few connections, heavy queries.

my-large.cnf
This is for a large system with memory = 512M where the system runs mainly.

my-medium.cnf
# This is for a system with little memory (32M - 64M) where MySQL plays
# an important part, or systems up to 128M where MySQL is used together with
# other programs (such as a web server)

my-small.cnf
# This is for a system with little memory (<= 64M) where MySQL is only used
# from time to time and it's important that the mysqld daemon
# doesn't use much resources.
 

我在之前的基礎上又使用了my-small.cnf的配置，記憶體降到350M，沒有到註釋的64M，估計安裝過程某一步的問題。