even update customer set showhelp=0 where cid=66 run 61 seconds

slow query below:

Time: 090706 15:12:30

User@Host: cfgbeam[cfgbeam] @ []

Query_time: 61 Lock_time: 0 Rows_sent: 0 Rows_examined: 0

update customer set showhelp=0 where cid=66;

CREATE TABLE customer (
cid int(10) unsigned NOT NULL,
bid int(11) default NULL,
cno varchar(32) NOT NULL,
ano varchar(cool: NOT NULL default ’ ',
cname varchar(20) NOT NULL default ’ ',
domain varchar(20) default NULL,
siteid varchar(cool: default NULL,
score decimal(18,2) NOT NULL default ‘5.00’,
money decimal(18,2) NOT NULL default ‘0.00’,
regdate datetime default NULL,
password varchar(32) default NULL,
status varchar(20) default ‘normal’,
memo varchar(255) default NULL,
passwderrortimes tinyint(4) default NULL,
currency varchar(3) NOT NULL default ‘RMB’,
email varchar(32) default NULL,
homepage varchar(255) default NULL,
rcv_email tinyint(4) default ‘1’ COMMENT ‘whether receive email notice’,
level tinyint(4) default ‘1’,
avatar varchar(255) default NULL,
avatar_big varchar(255) default NULL,
rmder_cid int(10) unsigned default NULL,
sex varchar(4) default NULL,
lst_login datetime default NULL,
email_active tinyint(4) default ‘0’,
kmoney int(11) default NULL,
login_fr varchar(20) default NULL,
UNIQUE KEY cno (cno),
UNIQUE KEY cid (cid)
it’s a sns game server,mysql so slow,it’s tuned a lots,
but event that update sql so slowly,

customer table only 150k records on a Xeon with 2G memory
somebody help me?any idea is very appreciated

That query is trivial. Are there any other queries in your slow query log? You could be looking at a symptom instead of the cause.

BTW, you can drop the unique index on cid, since it is already the primary key.