The FLUSH statement has several variant forms that clear or reload
various internal caches, flush tables, or acquire locks. To execute
FLUSH, you must have the RELOAD privilege. Specific flush options might
require additional privileges, as described later.
--查看cache index的帮助信息
mysql> help CACHE INDEX;
Name: 'CACHE INDEX'
Description:
Syntax:
CACHE INDEX
tbl_index_list [, tbl_index_list] ...
[PARTITION (partition_list | ALL)]
IN key_cache_name
tbl_index_list:
tbl_name [[INDEX|KEY] (index_name[, index_name] ...)]
partition_list:
partition_name[, partition_name][, ...]
........................
--比较常用的show 命令，通常查看系统变量，状态变量等
mysql> help show;
Name: 'SHOW'
Description:
SHOW has many forms that provide information about databases, tables,
columns, or status information about the server. This section describes
those following:
SHOW AUTHORS
SHOW {BINARY | MASTER} LOGS
--设置系统变量，用set 命令
mysql> help set;
Name: 'SET'
Description:
Syntax:
SET variable_assignment [, variable_assignment] ...
variable_assignment:
user_var_name = expr
| [GLOBAL | SESSION] system_var_name = expr
| [@@global. | @@session. | @@]system_var_name = expr
The SET statement assigns values to different types of variables that
affect the operation of the server or your client. Older versions of
MySQL employed SET OPTION, but this syntax is deprecated in favor of
SET without OPTION.
URL: http://dev.mysql.com/doc/refman/5.5/en/set-statement.html