SQL性能优化 Customer表定义如下 CREATE TABLE `t...

Question

SQL性能优化
Customer表定义如下
CREATE TABLE `test01` (
    custid` int(10) NOT NULL,
    custname` varchar(100) NOT NULL,
    date` datetime default NULL,
    money` int(10) default NULL,
    PRIMARY KEY  (`custid`),
    KEY `index_test01_custname` (`custname`),
    KEY `index_test01_custname_union` (`money`,` date`,`custname`,),
)
secondinfo 表定义如下
CREATE TABLE `test02` (
  secid` int(10) NOT NULL,
  firstid` int(10) NOT NULL,
  custid` int(10) default NULL,
  PRIMARY KEY (`secid`),
  KEY `Index_test02_custid` (`custid `)
)

下列SQL执行速度比较慢，请分析原因并做优化：

1)    SELECT  *  FROM  test01  WHERE  substring(custname,1,4)='beizhi'

2)    SELECT  *  FROM  test01  WHERE  money/30<1000 

3)    SELECT  *  FROM  test01  WHERE  custname=3721 

4)    SELECT * FROM test02 s WHERE s.custid NOT IN (SELECT c.custid FROM test01 c)

5)    select * from test01 where money<1000
union
select * from test01 where date >’20150101’